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                                                                    EXHIBIT 10.3

                       VOLTERRA SEMICONDUCTOR CORPORATION

                             1996 STOCK OPTION PLAN

                            ADOPTED OCTOBER 29, 1996
               ADOPTION APPROVED BY STOCKHOLDERS OCTOBER 29, 1996
                       AMENDED AND RESTATED JULY 31, 1997
       AMENDMENT AND RESTATEMENT APPROVED BY STOCKHOLDERS AUGUST 27, 1997
                      AMENDED AND RESTATED DECEMBER 4, 1997
      AMENDMENT AND RESTATEMENT APPROVED BY STOCKHOLDERS DECEMBER 16, 1997
                       AMENDED AND RESTATED JULY 17, 1998
         AMENDMENT AND RESTATEMENT APPROVED BY STOCKHOLDERS JULY 3, 1998
                       AMENDED AND RESTATED APRIL 24, 1999
        AMENDMENT AND RESTATEMENT APPROVED BY STOCKHOLDERS MARCH 1, 1999
                      AMENDED AND RESTATED OCTOBER 6, 1999
       AMENDMENT AND RESTATEMENT APPROVED BY STOCKHOLDERS OCTOBER 6, 1999
                      AMENDED AND RESTATED OCTOBER 12, 2000
                     AMENDED AND RESTATED NOVEMBER 30, 2000
      AMENDMENT AND RESTATEMENT APPROVED BY STOCKHOLDERS SEPTEMBER 27, 2001
                       AMENDED AND RESTATED JULY 23, 2002
        AMENDMENT AND RESTATEMENT APPROVED BY STOCKHOLDERS MARCH 27, 2003
                     AMENDED AND RESTATED APRIL 20, 2004
       AMENDMENT AND RESTATEMENT APPROVED BY STOCKHOLDERS _______________

1.    PURPOSES.

      (a)   The purpose of the Plan is to provide a means by which selected
Employees, Directors of and Consultants to the Company, and its Affiliates, may
be given an opportunity to purchase stock of the Company.

      (b)   The Company, by means of the Plan, seeks to retain the services of
persons who are now Employees or Directors of or Consultants to the Company or
its Affiliates, to secure and retain the services of new Employees, Directors
and Consultants, and to provide incentives for such persons to exert maximum
efforts for the success of the Company and its Affiliates.

      (c)   The Company intends that the Options issued under the Plan shall, in
the discretion of the Board or any Committee to which responsibility for
administration of the Plan has been delegated pursuant to subsection 3(c), be
either Incentive Stock Options or Nonstatutory Stock Options. All Options shall
be separately designated Incentive Stock Options or Nonstatutory Stock Options
at the time of grant, and in such form as issued pursuant to Section 6, and a
separate certificate or certificates will be issued for shares purchased on
exercise of each type of Option.

2.    DEFINITIONS.

      (a)   "AFFILIATE" means any parent corporation or subsidiary corporation,
whether now or hereafter existing, as those terms are defined in Sections 424(e)
and (f) respectively, of the Code.

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      (b)   "BOARD" means the Board of Directors of the Company.

      (c)   "CODE" means the Internal Revenue Code of 1986, as amended.

      (d)   "COMMITTEE" means a Committee appointed by the Board in accordance
with subsection 3(c) of the Plan.

      (e)   "COMPANY" means Volterra Semiconductor Corporation, a Delaware
corporation.

      (f)   "CONSULTANT" means any person, including an advisor, engaged by the
Company or an Affiliate to render consulting services and who is compensated for
such services, provided that the term "Consultant" shall not include Directors
who are paid only a director's fee by the Company or who are not compensated by
the Company for their services as Directors.

      (g)   "CONTINUOUS STATUS AS AN EMPLOYEE, DIRECTOR OR CONSULTANT" means
that the service of an individual to the Company, whether as an Employee,
Director or Consultant, is not interrupted or terminated. The Board or the chief
executive officer of the Company may determine, in that party's sole discretion,
whether Continuous Status as an Employee, Director or Consultant shall be
considered interrupted in the case of: (i) any leave of absence approved by the
Board or chief executive officer, including sick leave, military leave, or any
other personal leave; or (ii) transfers between the Company, Affiliates or their
successors.

      (h)   "COVERED EMPLOYEE" means the chief executive officer and the four
(4) other highest compensated officers of the Company for whom total
compensation is required to be reported to stockholders under the Exchange Act,
as determined for purposes of Section 162(m) of the Code.

      (i)   "DIRECTOR" means a member of the Board.

      (j)   "EMPLOYEE" means any person, including Officers and Directors,
employed by the Company or any Affiliate of the Company. Neither service as a
Director nor payment of a director's fee by the Company shall be sufficient to
constitute "employment" by the Company.

      (k)   "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
amended.

      (l)   "FAIR MARKET VALUE" means, as of any date, the value of the common
stock of the Company determined as follows and in each case in a manner
consistent with Section 260.140.50 of Title 10 of the California Code of
Regulations:

            (1)   If the common stock is listed on any established stock
exchange or traded on the Nasdaq National Market System or the Nasdaq SmallCap
Market, the Fair Market Value of a share of common stock shall be the closing
sales price for such stock (or the closing bid, if no sales were reported) as
quoted on such exchange or market (or the exchange or market with the greatest
volume of trading in the Company's common stock) on the last market trading day
prior to the day

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of determination, as reported in The Wall Street Journal or such other source as
the Board deems reliable;

            (2)   In the absence of such markets for the common stock, the Fair
Market Value shall be determined in good faith by the Board.

      (m)   "INCENTIVE STOCK OPTION" means an Option intended to qualify as an
incentive stock option within the meaning of Section 422 of the Code and the
regulations promulgated thereunder.

      (n)   "LISTING DATE" means the first date upon which any security of the
Company is listed (or approved for listing) upon notice of issuance on any
securities exchange, or designated (or approved for designation) upon notice of
issuance as a national market security on an interdealer quotation system if
such securities exchange or interdealer quotation system has been certified in
accordance with the provisions of Section 25100(o) of the California Corporate
Securities Law of 1968.

      (o)   "NON-EMPLOYEE DIRECTOR" means a Director who either (i) is not a
current Employee or Officer of the Company or its parent or subsidiary, does not
receive compensation (directly or indirectly) from the Company or its parent or
subsidiary for services rendered as a consultant or in any capacity other than
as a Director (except for an amount as to which disclosure would not be required
under Item 404(a) of Regulation S-K promulgated pursuant to the Securities Act
of 1933 ("Regulation S-K")), does not possess an interest in any other
transaction as to which disclosure would be required under Item 404(a) of
Regulation S-K, and is not engaged in a business relationship as to which
disclosure would be required under Item 404(b) of Regulation S-K; or (ii) is
otherwise considered a "non-employee director" for purposes of Rule 16b-3.

      (p)   "NONSTATUTORY STOCK OPTION" means an Option not intended to qualify
as an Incentive Stock Option.

      (q)   "OFFICER" means a person who is an officer of the Company within the
meaning of Section 16 of the Exchange Act and the rules and regulations
promulgated thereunder.

      (r)   "OPTION" means a stock option granted pursuant to the Plan.

      (s)   "OPTION AGREEMENT" means a written agreement between the Company and
an Optionee evidencing the terms and conditions of an individual Option grant.
Each Option Agreement shall be subject to the terms and conditions of the Plan.

      (t)   "OPTIONEE" means a person to whom an Option is granted pursuant to
the Plan, or, if applicable, such other person who holds an outstanding Option.

      (u)   "OUTSIDE DIRECTOR" means a Director who either (i) is not a current
employee of the Company or an "affiliated corporation" (within the meaning of
the Treasury regulations promulgated under Section 162(m) of the Code), is not a
former employee of the Company or an "affiliated corporation" receiving
compensation for prior services (other than benefits under a tax

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qualified pension plan), was not an officer of the Company or an "affiliated
corporation" at any time, and is not currently receiving direct or indirect
remuneration from the Company or an "affiliated corporation" for services in any
capacity other than as a Director, or (ii) is otherwise considered an "outside
director" for purposes of Section 162(m) of the Code.

      (v)   "PLAN" means this Volterra Semiconductor Corporation's Stock Option
Plan.

      (w)   "RULE 16b-3" means Rule 16b-3 of the Exchange Act or any successor
to Rule 16b-3, as in effect with respect to the Company at the time discretion
is being exercised regarding the Plan.

3.    ADMINISTRATION.

      (a)   The Plan shall be administered by the Board unless and until the
Board delegates administration to a Committee, as provided in subsection 3(c).

      (b)   The Board shall have the power, subject to, and within the
limitations of, the express provisions of the Plan:

            (1)   To determine from time to time which of the persons eligible
under the Plan shall be granted Options; when and how each Option shall be
granted; whether an Option will be an Incentive Stock Option or a Nonstatutory
Stock Option; the provisions of each Option granted (which need not be
identical), including the time or times such Option may be exercised in whole or
in part; and the number of shares for which an Option shall be granted to each
such person.

            (2)   To construe and interpret the Plan and Options granted under
it, and to establish, amend and revoke rules and regulations for its
administration. The Board, in the exercise of this power, may correct any
defect, omission or inconsistency in the Plan or in any Option Agreement, in a
manner and to the extent it shall deem necessary or expedient to make the Plan
fully effective.

            (3)   To amend the Plan or an Option as provided in Section 11.

            (4)   Generally, to exercise such powers and to perform such acts as
the Board deems necessary or expedient to promote the best interests of the
Company.

      (c)   The Board may delegate administration of the Plan to a committee of
the Board composed of not fewer than two (2) members (the "Committee"), all of
the members of which Committee may be, in the discretion of the Board,
Non-Employee Directors and/or Outside Directors. If administration is delegated
to a Committee, the Committee shall have, in connection with the administration
of the Plan, the powers theretofore possessed by the Board, including the power
to delegate to a subcommittee of two (2) or more Outside Directors any of the
administrative powers the Committee is authorized to exercise (and references in
this Plan to the Board shall thereafter be to the Committee or such a
subcommittee), subject, however, to such resolutions, not inconsistent with the
provisions of the Plan, as may be adopted from time to time by the Board. The
Board may abolish the Committee at any time and revest in the Board the
administration of the

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Plan. Additionally, prior to the Listing Date and notwithstanding anything to
the contrary contained herein, the Board may delegate administration of the Plan
to a committee of one or more members of the Board and the term "Committee"
shall apply to any person or persons to whom such authority has been delegated.
Notwithstanding anything in this Section 3 to the contrary, the Board or the
Committee may delegate to a committee of one or more members of the Board the
authority to grant Options to eligible persons who (1) are not then subject to
Section 16 of the Exchange Act and/or (2) are either (i) not then Covered
Employees and are not expected to be Covered Employees at the time of
recognition of income resulting from such Option, or (ii) not persons with
respect to whom the Company wishes to comply with Section 162(m) of the Code.

4.    SHARES SUBJECT TO THE PLAN.

      (a)   Subject to the provisions of Section 10 relating to adjustments upon
changes in stock, the stock that may be sold pursuant to Options shall not
exceed in the aggregate thirteen million four hundred sixty-seven thousand five
hundred (13,467,500) shares of the Company's common stock. If any Option shall
for any reason expire or otherwise terminate, in whole or in part, without
having been exercised in full, the stock not purchased under such Option shall
revert to and again become available for issuance under the Plan.

      (b)   The stock subject to the Plan may be unissued shares or reacquired
shares, bought on the market or otherwise.

5.   ELIGIBILITY.

      (a)   Incentive Stock Options may be granted only to Employees.
Nonstatutory Stock Options may be granted only to Employees, Directors or
Consultants.

      (b)   No person shall be eligible for the grant of an Option if, at the
time of grant, such person owns (or is deemed to own pursuant to Section 424(d)
of the Code) stock possessing more than ten percent (10%) of the total combined
voting power of all classes of stock of the Company or of any of its Affiliates
unless the exercise price of such Option is at least one hundred ten percent
(110%) of the Fair Market Value of such stock at the date of grant and the
Option is not exercisable after the expiration of five (5) years from the date
of grant.

      (c)   Subject to the provisions of Section 10 relating to adjustments upon
changes in stock, no person shall be eligible to be granted Options covering
more than two hundred thousand (200,000) shares of the Company's common stock in
any calendar year period. This subsection 5(c) shall not apply prior to the
Listing Date and, following the Listing Date, shall not apply until (i) the
earliest of: (A) the first material modification of the Plan (including any
increase to the number of shares reserved for issuance under the Plan in
accordance with Section 4); (B) the issuance of all of the shares of common
stock reserved for issuance under the Plan; (C) the expiration of the Plan; or
(D) the first meeting of stockholders at which directors are to be elected that
occurs after the close of the third calendar year following the calendar year in
which occurred the first registration of an equity security under Section 12 of
the Exchange Act; or (ii) such other date required by Section 162(m) of the Code
and the rules and regulations promulgated thereunder.

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6.    OPTION PROVISIONS.

      Each Option shall be in such form and shall contain such terms and
conditions as the Board shall deem appropriate. The provisions of separate
Options need not be identical, but each Option shall include (through
incorporation of provisions hereof by reference in the Option or otherwise) the
substance of each of the following provisions:

      (a)   TERM. No Option shall be exercisable after the expiration of ten
(10) years from the date it was granted.

      (b)   PRICE. The exercise price of each Incentive Stock Option shall be
not less than one hundred percent (100%) of the Fair Market Value of the stock
subject to the Option on the date the Option is granted; the exercise price of
each Nonstatutory Stock Option shall be not less than eighty-five percent (85%)
of the Fair Market Value of the stock subject to the Option on the date the
Option is granted. Notwithstanding the foregoing, an Option (whether an
Incentive Stock Option or a Nonstatutory Stock Option) may be granted with an
exercise price lower than that set forth in the preceding sentence if such
Option is granted pursuant to an assumption or substitution for another option
in a manner satisfying the provisions of Section 424(a) of the Code.

      (c)   CONSIDERATION. The purchase price of stock acquired pursuant to an
Option shall be paid, to the extent permitted by applicable statutes and
regulations, either (i) in cash at the time the Option is exercised, or (ii) at
the discretion of the Board or the Committee, at the time of the grant of the
Option, (A) by delivery to the Company of other common stock of the Company, (B)
according to a deferred payment arrangement, except that payment of the common
stock's "par value" (as defined in the Delaware General Corporation Law) shall
not be made by deferred payment, or other arrangement (which may include,
without limiting the generality of the foregoing, the use of other common stock
of the Company) with the person to whom the Option is granted or to whom the
Option is transferred pursuant to subsection 6(d), or (C) in any other form of
legal consideration that may be acceptable to the Board.

      In the case of any deferred payment arrangement, interest shall be payable
at least annually and shall be charged at the minimum rate of interest necessary
to avoid the treatment as interest, under any applicable provisions of the Code,
of any amounts other than amounts stated to be interest under the deferred
payment arrangement.

      (d)   TRANSFERABILITY. An Option shall not be transferable except by will
or by the laws of descent and distribution, and shall be exercisable during the
lifetime of the person to whom the Option is granted only by such person.

      (e)   VESTING. The total number of shares of stock subject to an Option
may, but need not, be allotted in periodic installments (which may, but need
not, be equal). The Option Agreement may provide that from time to time during
each of such installment periods, the Option may become exercisable ("vest")
with respect to some or all of the shares allotted to that period, and may be
exercised with respect to some or all of the shares allotted to such period
and/or any prior period as to which the Option became vested but was not fully
exercised. The Option may be subject to such other terms and conditions on the
time or times when it may be exercised (which

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may be based on performance or other criteria) as the Board may deem
appropriate. The vesting provisions of individual Options may vary but in each
case will provide for vesting of at least twenty percent (20%) per year of the
total number of shares subject to the Option. The provisions of this subsection
6(e) are subject to any Option provisions governing the minimum number of shares
as to which an Option may be exercised.

      (f)   SECURITIES LAW COMPLIANCE. The Company may require any Optionee, or
any person to whom an Option is transferred under subsection 6(d), as a
condition of exercising any such Option, (1) to give written assurances
satisfactory to the Company as to the Optionee's knowledge and experience in
financial and business matters and/or to employ a purchaser representative
reasonably satisfactory to the Company who is knowledgeable and experienced in
financial and business matters, and that he or she is capable of evaluating,
alone or together with the purchaser representative, the merits and risks of
exercising the Option; and (2) to give written assurances satisfactory to the
Company stating that such person is acquiring the stock subject to the Option
for such person's own account and not with any present intention of selling or
otherwise distributing the stock. The foregoing requirements, and any assurances
given pursuant to such requirements, shall be inoperative if (i) the issuance of
the shares upon the exercise of the Option has been registered under a then
currently effective registration statement under the Securities Act of 1933, as
amended (the "Securities Act"), or (ii) as to any particular requirement, a
determination is made by counsel for the Company that such requirement need not
be met in the circumstances under the then applicable securities laws. The
Company may require the Optionee to provide such other representations, written
assurances or information which the Company shall determine is necessary,
desirable or appropriate to comply with applicable securities and other laws as
a condition of granting an Option to such Optionee or permitting the Optionee to
exercise such Option. The Company may, upon advice of counsel to the Company,
place legends on stock certificates issued under the Plan as such counsel deems
necessary or appropriate in order to comply with applicable securities laws,
including, but not limited to, legends restricting the transfer of the stock.

      (g)   TERMINATION OF EMPLOYMENT OR RELATIONSHIP AS A DIRECTOR OR
CONSULTANT. In the event an Optionee's Continuous Status as an Employee,
Director or Consultant terminates (other than upon the Optionee's death or
disability), the Optionee may exercise his or her Option (to the extent that the
Optionee was entitled to exercise it as of the date of termination) but only
within such period of time ending on the earlier of (i) the date three (3)
months after the termination of the Optionee's Continuous Status as an Employee,
Director or Consultant, or such longer or shorter period, which in no event
shall be less than thirty (30) days, specified in the Option Agreement, or (ii)
the expiration of the term of the Option as set forth in the Option Agreement.
If, at the date of termination, the Optionee is not entitled to exercise his or
her entire Option, the shares covered by the unexercisable portion of the Option
shall revert to and again become available for issuance under the Plan. If,
after termination, the Optionee does not exercise his or her Option within the
time specified in the Option Agreement, the Option shall terminate, and the
shares covered by such Option shall revert to and again become available for
issuance under the Plan.

      (h)   DISABILITY OF OPTIONEE. In the event an Optionee's Continuous Status
as an Employee, Director or Consultant terminates as a result of the Optionee's
disability, the Optionee may exercise his or her Option (to the extent that the
Optionee was entitled to exercise it as of the

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date of termination), but only within such period of time ending on the earlier
of (i) the date twelve (12) months following such termination (or such longer or
shorter period, which in no event shall be less than six (6) months, specified
in the Option Agreement), or (ii) the expiration of the term of the Option as
set forth in the Option Agreement. If, at the date of termination, the Optionee
is not entitled to exercise his or her entire Option, the shares covered by the
unexercisable portion of the Option shall revert to and again become available
for issuance under the Plan. If, after termination, the Optionee does not
exercise his or her Option within the time specified herein, the Option shall
terminate, and the shares covered by such Option shall revert to and again
become available for issuance under the Plan.

      (i)   DEATH OF OPTIONEE. In the event of the death of an Optionee during,
or within a period specified in the Option Agreement after the termination of,
the Optionee's Continuous Status as an Employee, Director or Consultant, the
Option may be exercised (to the extent the Optionee was entitled to exercise the
Option as of the date of death) by the Optionee's estate, by a person who
acquired the right to exercise the Option by bequest or inheritance or by a
person designated to exercise the option upon the Optionee's death pursuant to
subsection 6(d), but only within the period ending on the earlier of (i) the
date eighteen (18) months following the date of death (or such longer or shorter
period, which in no event shall be less than six (6) months, specified in the
Option Agreement), or (ii) the expiration of the term of such Option as set
forth in the Option Agreement. If, at the time of death, the Optionee was not
entitled to exercise his or her entire Option, the shares covered by the
unexercisable portion of the Option shall revert to and again become available
for issuance under the Plan. If, after death, the Option is not exercised within
the time specified herein, the Option shall terminate, and the shares covered by
such Option shall revert to and again become available for issuance under the
Plan.

      (j)   EARLY EXERCISE. The Option may, but need not, include a provision
whereby the Optionee may elect at any time while an Employee, Director or
Consultant to exercise the Option as to any part or all of the shares subject to
the Option prior to the full vesting of the Option. Any unvested shares so
purchased shall be subject to a repurchase right in favor of the Company, with
the repurchase price to be equal to the original purchase price of the stock, or
to any other restriction the Board determines to be appropriate; provided,
however, that (i) the right to repurchase at the original purchase price shall
lapse at a minimum rate of twenty percent (20%) per year over five (5) years
from the date the Option was granted, and (ii) such right shall be exercisable
only within (A) the ninety (90) day period following the termination of
employment or the relationship as a Director or Consultant or (B) such longer
period as may be agreed to by the Company and the Optionee (for example, for
purposes of satisfying the requirements of Section 1202(c)(3) of the Code
(regarding "qualified small business stock")), and (iii) such right shall be
exercisable only for cash or cancellation of purchase money indebtedness for the
shares. Should the right of repurchase be assigned by the Company, the assignee
shall pay the Company cash equal to the difference between the original purchase
price and the stock's Fair Market Value if the original purchase price is less
than the stock's Fair Market Value.

      (k)   RIGHT OF REPURCHASE. The Option may, but need not, include a
provision whereby the Company may elect, prior to the Listing Date to repurchase
all or any part of the vested shares exercised pursuant to the Option; provided,
however, that (i) such repurchase right shall be exercisable only within (A) the
ninety (90) day period following the termination of employment or

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the relationship as a Director or Consultant or (B) such longer period as may be
agreed to by the Company and the Optionee (for example, for purposes of
satisfying the requirements of Section 1202(c)(3) of the Code (regarding
"qualified small business stock")), (ii) such repurchase right shall be
exerciseable for less than all of the vested shares only with the Optionee's
consent, and (iii) such right shall be exercisable only for cash or cancellation
of purchase money indebtedness for the shares at a repurchase price equal to the
greater of (A) the stock's Fair Market Value at the time of such termination, or
(B) the original purchase price paid for such shares by the Optionee. Should the
right of repurchase be assigned by the Company, the assignee shall pay the
Company cash equal to the difference between the original purchase price and the
stock's Fair Market Value if the original purchase price is less than the
stock's Fair Market Value.

      (l)   RIGHT OF FIRST REFUSAL. The Option may, but need not, include a
provision whereby the Company may elect, prior to the Listing Date, to exercise
a right of first refusal following receipt of notice from the Optionee of the
intent to transfer all or any part of the shares exercised pursuant to the
Option. Such right of first refusal shall be exercised by the Company no more
than thirty (30) days following receipt of notice of the Optionee's intent to
transfer shares and must be exercised as to all the shares the Optionee intends
to transfer unless the Optionee consents to exercise for less than all the
shares offered. The purchase of the shares following exercise shall be completed
within thirty (30) days of the Company's receipt of notice of the Optionee's
intent to transfer shares or such longer period of time as has been offered by
the person to whom the Optionee intends to transfer the shares, or as may be
agreed to by the Company and the Optionee (for example, for purposes of
satisfying the requirements of Section 1202(c)(3) of the Code (regarding
"qualified small business stock"). Except as expressly provided in this
Subsection (l), such right of first refusal shall otherwise comply with the
provisions of the Bylaws of the Company. Such right of first refusal shall
otherwise comply with the provisions of the Bylaws of the Company.

      (m)   WITHHOLDING. To the extent provided by the terms of an Option
Agreement, the Optionee may satisfy any federal, state or local tax withholding
obligation relating to the exercise of such Option by any of the following means
or by a combination of such means: (1) tendering a cash payment; (2) authorizing
the Company to withhold shares from the shares of the common stock otherwise
issuable to the Optionee as a result of the exercise of the Option; or (3)
delivering to the Company owned and unencumbered shares of the common stock of
the Company.

7.    COVENANTS OF THE COMPANY.

      (a)   During the terms of the Options, the Company shall keep available at
all times the number of shares of stock required to satisfy such Options.

      (b)   The Company shall seek to obtain from each regulatory commission or
agency having jurisdiction over the Plan such authority as may be required to
issue and sell shares of stock upon exercise of the Options; provided, however,
that this undertaking shall not require the Company to register under the
Securities Act either the Plan, any Option or any stock issued or issuable
pursuant to any such Option. If, after reasonable efforts, the Company is unable
to obtain from any such regulatory commission or agency the authority which
counsel for the Company deems necessary for the lawful issuance and sale of
stock under the Plan, the Company shall be

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relieved from any liability for failure to issue and sell stock upon exercise of
such Options unless and until such authority is obtained.

8.    USE OF PROCEEDS FROM STOCK.

      Proceeds from the sale of stock pursuant to Options shall constitute
general funds of the Company.

9.    MISCELLANEOUS.

      (a)   Subject to any applicable provisions of the California Corporate
Securities Law of 1968 and related regulations relied upon as a condition of
issuing securities pursuant to the Plan, the Board shall have the power to
accelerate the time at which an Option may first be exercised or the time during
which an Option or any part thereof will vest pursuant to subsection 6(e),
notwithstanding the provisions in the Option stating the time at which it may
first be exercised or the time during which it will vest.

      (b)   Neither an Optionee nor any person to whom an Option is transferred
under subsection 6(d) shall be deemed to be the holder of, or to have any of the
rights of a holder with respect to, any shares subject to such Option unless and
until such person has satisfied all requirements for exercise of the Option
pursuant to its terms.

      (c)   Throughout the term of any Option, the Company shall deliver to the
holder of such Option, not later than one hundred twenty (120) days after the
close of each of the Company's fiscal years during the Option term, a balance
sheet and an income statement. This section shall not apply (i) after the
Listing Date or (ii) when issuance is limited to key employees whose duties in
connection with the Company assure them access to equivalent information.

      (d)   Nothing in the Plan or any instrument executed or Option granted
pursuant thereto shall confer upon any Employee, Director, Consultant or
Optionee any right to continue in the employ of the Company or any Affiliate (or
to continue acting as a Director or Consultant) or shall affect the right of the
Company or any Affiliate to terminate the employment of any Employee, with or
without cause, to remove any Director as provided in the Company's By-Laws and
the provisions of the General Corporation Law of the State of Delaware, or to
terminate the relationship of any Consultant subject to the terms of that
Consultant's agreement with the Company or Affiliate to which such Consultant is
providing services.

      (e)   To the extent that the aggregate Fair Market Value (determined at
the time of grant) of stock with respect to which Incentive Stock Options are
exercisable for the first time by any Optionee during any calendar year under
all plans of the Company and its Affiliates exceeds one hundred thousand dollars
($100,000), the Options or portions thereof which exceed such limit (according
to the order in which they were granted) shall be treated as Nonstatutory Stock
Options.

      (f)   (1)     The Board or the Committee shall have the authority to
effect, at any time and from time to time (i) the repricing of any outstanding
Options under the Plan and/or (ii) with the consent of the affected holders of
Options, the cancellation of any outstanding Options and the grant

                                       10

<PAGE>

in substitution therefor of new Options under the Plan covering the same or
different numbers of shares of common stock, but having an exercise price per
share not less than eighty-five percent (85%) of the Fair Market Value in the
case of a Nonstatutory Stock Option (one hundred percent (100%) of the Fair
Market Value in the case of an Incentive Stock Option or, in the case of a ten
percent (10%) stockholder (as defined in subsection 5(b)), not less than one
hundred and ten percent (110%) of the Fair Market Value) per share of common
stock on the new grant date.

            (2)   Shares subject to an Option canceled under this subsection
9(f) shall continue to be counted against the maximum award of Options permitted
to be granted pursuant to subsection 5(c) of the Plan. The repricing of an
Option under this subsection 9(f), resulting in a reduction of the exercise
price, shall be deemed to be a cancellation of the original Option and the grant
of a substitute Option; in the event of such repricing, both the original and
the substituted Options shall be counted against the maximum awards of Options
permitted to be granted pursuant to subsection 5(c) of the Plan. The provisions
of this subsection 9(f) shall be applicable only to the extent required by
Section 162(m) of the Code.

10.   ADJUSTMENTS UPON CHANGES IN STOCK.

      (a)   If any change is made in the stock subject to the Plan, or subject
to any Option (through merger, consolidation, reorganization, recapitalization,
stock dividend, dividend in property other than cash, stock split, liquidating
dividend, combination of shares, exchange of shares, change in corporate
structure or other transaction not involving the receipt of consideration by the
Company), the Plan will be appropriately adjusted in the type(s) and maximum
number of securities subject to the Plan pursuant to subsection 4(a) and the
maximum number of securities subject to award to any person during any calendar
year period pursuant to subsection 5(c), and the outstanding Options will be
appropriately adjusted in the type(s) and number of securities and price per
share of stock subject to such outstanding Options. Such adjustments shall be
made by the Board or Committee, the determination of which shall be final,
binding and conclusive. (The conversion of any convertible securities of the
Company shall not be treated as a "transaction not involving the receipt of
consideration by the Company.")

      (b)   In the event of: (1) a dissolution, liquidation, or sale of all or
substantially all of the assets of the Company; (2) a merger or consolidation in
which the Company is not the surviving corporation; or (3) a reverse merger in
which the Company is the surviving corporation but the shares of the Company's
common stock outstanding immediately preceding the merger are converted by
virtue of the merger into other property, whether in the form of securities,
cash or otherwise, then: (i) any surviving or acquiring corporation shall assume
Options outstanding under the Plan or shall substitute similar options
(including an option to acquire the same consideration paid to stockholders in
the transaction described in this Subsection 10(b)) for those outstanding under
the Plan, or (ii) in the event any surviving or acquiring corporation refuses to
assume such Options or to substitute similar options for those outstanding under
the Plan, (A) with respect to Options held by persons then performing services
as Employees, Directors or Consultants and subject to any applicable provisions
of the California Corporate Securities Law of 1968 and related regulations
relied upon as a condition of issuing securities pursuant to the Plan, the
vesting of such Options and the time during which such Options may be exercised
shall be accelerated prior to such event and the Options terminated if not
exercised after such acceleration and at or prior to such

                                       11

<PAGE>

event, and (B) with respect to any other Options outstanding under the Plan,
such Options shall be terminated if not exercised prior to such event.

11.   AMENDMENT OF THE PLAN AND OPTIONS.

      (a)   The Board at any time, and from time to time, may amend the Plan.
However, except as provided in Section 10 relating to adjustments upon changes
in stock, no amendment shall be effective unless approved by the stockholders of
the Company within twelve (12) months before or after the adoption of the
amendment, where the amendment will:

            (1)   Increase the number of shares reserved for Options under the
Plan;

            (2)   Modify the requirements as to eligibility for participation in
the Plan (to the extent such modification requires stockholder approval in order
for the Plan to satisfy the requirements of Section 422 of the Code); or

            (3)   Modify the Plan in any other way if such modification requires
stockholder approval in order for the Plan to satisfy the requirements of
Section 422 of the Code or to comply with the requirements of Rule 16b-3.

      (b)   The Board may in its sole discretion submit any other amendment to
the Plan for stockholder approval, including, but not limited to, amendments to
the Plan intended to satisfy the requirements of Section 162(m) of the Code and
the regulations promulgated thereunder regarding the exclusion of
performance-based compensation from the limit on corporate deductibility of
compensation paid to certain executive officers.

      (c)   It is expressly contemplated that the Board may amend the Plan in
any respect the Board deems necessary or advisable to provide Optionees with the
maximum benefits provided or to be provided under the provisions of the Code and
the regulations promulgated thereunder relating to Incentive Stock Options
and/or to bring the Plan and/or Incentive Stock Options granted under it into
compliance therewith.

      (d)   Rights and obligations under any Option granted before amendment of
the Plan shall not be impaired by any amendment of the Plan unless (i) the
Company requests the consent of the person to whom the Option was granted and
(ii) such person consents in writing.

      (e)   The Board at any time, and from time to time, may amend the terms of
any one or more Options; provided, however, that the rights and obligations
under any Option shall not be impaired by any such amendment unless (i) the
Company requests the consent of the person to whom the Option was granted and
(ii) such person consents in writing.

12.   TERMINATION OR SUSPENSION OF THE PLAN.

      (a)   The Board may suspend or terminate the Plan at any time. Unless
sooner terminated, the Plan shall terminate on October 28, 2006, which shall be
within ten (10) years from the date the Plan is adopted by the Board or approved
by the stockholders of the Company,

                                       12

<PAGE>

whichever is earlier. No Options may be granted under the Plan while the Plan is
suspended or after it is terminated.

      (b)   Rights and obligations under any Option granted while the Plan is in
effect shall not be impaired by suspension or termination of the Plan, except
with the written consent of the person to whom the Option was granted.

13.   EFFECTIVE DATE OF PLAN.

      The Plan shall become effective as determined by the Board, but no Options
granted under the Plan shall be exercised unless and until the Plan has been
approved by the stockholders of the Company, which approval shall be within
twelve (12) months before or after the date the Plan is adopted by the Board,
and, if required, an appropriate permit has been issued by the Commissioner of
Corporations of the State of California.

                                       13

<PAGE>

                                                         Grant Date:  ,
                                                         Number of Shares:
                                                         Exercise Price: $
                                                         Total Exercise Price: $

                             INCENTIVE STOCK OPTION

      Optionee:

      VOLTERRA SEMICONDUCTOR CORPORATION (the "Company"), pursuant to its 1996
Stock Option Plan (the "Plan"), has granted to you, the optionee named above, an
option to purchase shares of the common stock of the Company ("Common Stock").
This option is intended to qualify as an "incentive stock option" within the
meaning of Section 422 of the Internal Revenue Code of 1986, as amended (the
"Code").

      The grant hereunder is in connection with and in furtherance of the
Company's compensatory benefit plan for participation of the Company's employees
(including officers), directors or consultants and is intended to comply with
the provisions of Rule 701 promulgated y the Securities and Exchange Commission
under the Securities Act of 1933, as amended (the "Act"). The grant of this
option and the issuance of shares upon the exercise of this option are also
intended to be exempt from the securities qualification requirements of the
California Corporations Code pursuant to Section 25102(o) of that code. Defined
terms not explicitly defined in this agreement but defined in the Plan shall
have the same definitions as in the Plan.

      The details of your option are as follows:

      1.    TOTAL NUMBER OF SHARES SUBJECT TO THIS OPTION. The total number of
shares of Common Stock subject to this option is ().

      2.    VESTING. Subject to the limitations contained herein, 25% of the
shares will vest (become exercisable) on          ,           (one year from the
date vesting commences) and 6.25% of the shares will then vest each quarter
thereafter until either (i) you cease employment with the Company for any
reason, or (ii) this option becomes fully vested.

      3.    EXERCISE PRICE AND METHOD OF PAYMENT.

            (a)   EXERCISE PRICE. The exercise price of this option is
($          ) per share, being not less than the fair market value of the Common
Stock on the date of grant of this option.

            (b)   METHOD OF PAYMENT. Payment of the exercise price per share is
due in full upon exercise of all or any part of each installment which has
accrued to you. You may

                                       1

<PAGE>

elect, to the extent permitted by applicable statutes and regulations, to make
payment of the exercise price under one of the following alternatives:

                        (i)   Payment of the exercise price per share in cash
(including check) at the time of exercise;

                        (ii)  Payment pursuant to a program developed under
Regulation T as promulgated by the Federal Reserve Board which, prior to the
issuance of Common Stock, results in either the receipt of cash (or check) by
the Company or the receipt of irrevocable instructions to pay the aggregate
exercise price to the Company from the sales proceeds;

                        (iii) Provided that at the time of exercise the
Company's Common Stock is publicly traded and quoted regularly in the Wall
Street Journal, payment by delivery of already-owned shares of Common Stock,
held for the period required to avoid a charge to the Company's reported
earnings, and owned free and clear of any liens, claims, encumbrances or
security interests, which Common Stock shall be valued at its fair market value
on the date of exercise; or

                        (iv)  Payment by a combination of the methods of payment
permitted by subparagraph 3(b)(i) through 3(b)(iii) above.

      4.    WHOLE SHARES. This option may not be exercised for any number of
shares which would require the issuance of anything other than whole shares.

      5.    SECURITIES LAW COMPLIANCE. Notwithstanding anything to the contrary
contained herein, this option may not be exercised unless the shares issuable
upon exercise of this option are then registered under the Act or, if such
shares are not then so registered, the Company has determined that such exercise
and issuance would be exempt from the registration requirements of the Act.

      6.    TERM. The term of this option commences on        ,           , the
date of grant, and expires on         ,          (the "Expiration Date," which
date shall be no more than ten (10) years from the date this option is granted),
unless this option expires sooner as set forth below or in the Plan. In no event
may this option be exercised on or after the Expiration Date. This option shall
terminate prior to the Expiration Date as follows: three (3) months after the
termination of your Continuous Status as an Employee, Director or Consultant
with the Company or an Affiliate of the Company unless one of the following
circumstances exists:

            (a)   Your termination of Continuous Status as an Employee, Director
or Consultant is due to your permanent and total disability (within the meaning
of Section 422(c)(6) of the Code). This option will then expire on the earlier
of the Expiration Date set forth above or twelve (12) months following such
termination of Continuous Status as an Employee, Director or Consultant.

                                       2

<PAGE>

            (b)   Your termination of Continuous Status as an Employee, Director
or Consultant is due to your death or your death occurs within three (3) months
following your termination of Continuous Status as an Employee, Director or
Consultant for any other reason. This option will then expire on the earlier of
the Expiration Date set forth above or eighteen (18) months after your death.

            (c)   If during any part of such three (3) month period you may not
exercise your option solely because of the condition set forth in paragraph 5
above, then your option will not expire until the earlier of the Expiration Date
set forth above or until this option shall have been exercisable for an
aggregate period of three (3) months after your termination of Continuous Status
as an Employee, Director or Consultant.

            (d)   If your exercise of the option within three (3) months after
termination of your Continuous Status as an Employee, Director or Consultant
with the Company or with an Affiliate of the Company would result in liability
under section 16(b) of the Securities Exchange Act of 1934, then your option
will expire on the earlier of (i) the Expiration Date set forth above, (ii) the
tenth (10th) day after the last date upon which exercise would result in such
liability or (iii) six (6) months and ten (10) days after the termination of
your Continuous Status as an Employee, Director or Consultant with the Company
or an Affiliate of the Company.

      However, this option may be exercised following termination of Continuous
Status as an Employee, Director or Consultant only as to that number of shares
as to which it was exercisable on the date of termination of Continuous Status
as an Employee, Director or Consultant under the provisions of paragraph 2 of
this option.

      In order to obtain the federal income tax advantages associated with an
"incentive stock option," the Code requires that at all times beginning on the
date of grant of the option and ending on the day three (3) months before the
date of the option's exercise, you must be an employee of the Company or an
Affiliate of the Company, except in the event of your death or permanent and
total disability. The Company has provided for continued vesting or extended
exercisability of your option under certain circumstances for your benefit, but
cannot guarantee that your option will necessarily be treated as an "incentive
stock option" if you provide services to the Company or an Affiliate of the
Company as a consultant or exercise your option more than three (3) months after
the date your employment with the Company and all Affiliates of the Company
terminates.

      7.    EXERCISE.

            (a)   This option may be exercised, to the extent specified above,
by delivering a notice of exercise (in a form designated by the Company)
together with the exercise price to the Secretary of the Company, or to such
other person as the Company may designate, during regular business hours,
together with such additional documents as the Company may then require pursuant
to subsection 6(f) of the Plan.

            (b)   By exercising this option you agree that:

                                       3

<PAGE>

                        (i)   as a precondition to the completion of any
exercise of this option, the Company may require you to enter an arrangement
providing for the payment by you to the Company of any tax withholding
obligation of the Company arising by reason of (1) the exercise of this option;
(2) the lapse of any substantial risk of forfeiture to which the shares are
subject at the time of exercise; or (3) the disposition of shares acquired upon
such exercise;

                        (ii)  you will notify the Company in writing within
fifteen (15) days after the date of any disposition of any of the shares of the
Common Stock issued upon exercise of this option that occurs within two (2)
years after the date of this option grant or within one (1) year after such
shares of Common Stock are transferred upon exercise of this option; and

                        (iii) the Company (or a representative of the
underwriters) may, in connection with the first underwritten registration of the
offering of any securities of the Company under the Act, require that you not
sell or otherwise transfer or dispose of any shares of Common Stock or other
securities of the Company during such period (not to exceed one hundred eighty
(180) days) following the effective date (the "Effective Date") of the
registration statement of the Company filed under the Act as may be requested by
the Company or the representative of the underwriters. You further agree that
the Company may impose stop-transfer instructions with respect to securities
subject to the foregoing restrictions until the end of such period.

      8.    TRANSFERABILITY. This option is not transferable, except by will or
by the laws of descent and distribution, and is exercisable during your life
only by you. Notwithstanding the foregoing, by delivering written notice to the
Company, in a form satisfactory to the Company, you may designate a third party
who, in the event of your death, shall thereafter be entitled to exercise this
option.

      9.    OPTION NOT A SERVICE CONTRACT. This option is not an employment
contract and nothing in this option shall be deemed to create in any way
whatsoever any obligation on your part to continue in the employ of the Company,
or of the Company to continue your employment with the Company. In addition,
nothing in this option shall obligate the Company or any Affiliate of the
Company, or their respective shareholders, Board of Directors, officers or
employees to continue any relationship which you might have as a Director or
Consultant for the Company or Affiliate of the Company.

      10.   NOTICES. Any notices provided for in this option or the Plan shall
be given in writing and shall be deemed effectively given upon receipt or, in
the case of notices delivered by the Company to you, five (5) days after deposit
in the United States mail, postage prepaid, addressed to you at the address
specified below or at such other address as you hereafter designate by written
notice to the Company.

                                       4

<PAGE>

      11.   GOVERNING PLAN DOCUMENT. This option is subject to all the
provisions of the Plan, a copy of which is attached hereto and its provisions
are hereby made a part of this option, including without limitation the
provisions of Section 6 of the Plan relating to option provisions, and is
further subject to all interpretations, amendments, rules and regulations which
may from time to time be promulgated and adopted pursuant to the Plan. In the
event of any conflict between the provisions of this option and those of the
Plan, the provisions of the Plan shall control.

      Dated the day of

                                                   Very truly yours,

                                                   _____________________________
                                                   Greg Hildebrand
                                                   Director of Finance

                                                   Duly authorized on behalf
                                                   of the Board of Directors

ATTACHMENTS:

      Notice of Exercise

                                       5

<PAGE>

                                                      Grant Date:   ,
                                                      Number of Shares:
                                                      Exercise Price: $
                                                      Total Exercise Price: $

The undersigned:

      (a)   Acknowledges receipt of the foregoing option and the attachments
referenced therein and understands that all rights and liabilities with respect
to this option are set forth in the option and the Plan; and

      (b)   Acknowledges that as of the date of grant of this option, it sets
forth the entire understanding between the undersigned optionee and the Company
and its Affiliates regarding the acquisition of stock in the Company and
supersedes all prior oral and written agreements on that subject with the
exception of (i) the options previously granted and delivered to the undersigned
under stock option plans of the Company, and (ii) the following agreements only:

      NONE     _________________________
               (Initial)

      OTHER

              ___________________________________________
              ___________________________________________
              ___________________________________________

                                               ________________________________

                                               OPTIONEE

                                               Address:

                                       6

<PAGE>

                                                         Grant Date:
                                                         Number of Shares:
                                                         Exercise Price: $
                                                         Total Exercise Price: $

                            NONSTATUTORY STOCK OPTION

      , Optionee:

      VOLTERRA SEMICONDUCTOR CORPORATION (the "Company"), pursuant to its 1996
Stock Option Plan (the "Plan"), has granted to you, the optionee named above, an
option to purchase shares of the common stock of the Company ("Common Stock").
This option is not intended to qualify and will not be treated as an "incentive
stock option" within the meaning of Section 422 of the Internal Revenue Code of
1986, as amended (the "Code").

      The grant hereunder is in connection with and in furtherance of the
Company's compensatory benefit plan for participation of the Company's employees
(including officers), directors or consultants and is intended to comply with
the provisions of Rule 701 promulgated by the Securities and Exchange Commission
under the Securities Act of 1933, as amended (the "Act"). The grant of this
option and the issuance of shares upon the exercise of this option are also
intended to be exempt from the securities qualification requirements of the
California Corporations Code pursuant to Section 25102(o) of that code. Defined
terms not explicitly defined in this agreement but defined in the Plan shall
have the same definitions as in the Plan.

      The details of your option are as follows:

      1.    TOTAL NUMBER OF SHARES SUBJECT TO THIS OPTION. The total number of
shares of Common Stock subject to this option is        (      ).

      2.    VESTING. Subject to the limitations contained herein, 25% of the
shares will vest (become exercisable) on        ,        (one year from the date
vesting commences) and 6.25% of the shares will then vest each quarter
thereafter until either (i) you cease to provide services to the Company for any
reason, or (ii) this option becomes fully vested.

      3.    EXERCISE PRICE AND METHOD OF PAYMENT.

            (a)   EXERCISE PRICE. The exercise price of this option is
($        ) per share, being not less than 85% of the fair market value of the
Common Stock on the date of grant of this option.

            (b)   METHOD OF PAYMENT. Payment of the exercise price per share is
due in full

<PAGE>

upon exercise of all or any part of each installment which has accrued to you.
You may elect, to the extent permitted by applicable statutes and regulations,
to make payment of the exercise price under one of the following alternatives:

                        (i)   Payment of the exercise price per share in cash
(including check) at the time of exercise;

                        (ii)  Payment pursuant to a program developed under
Regulation T as promulgated by the Federal Reserve Board which, prior to the
issuance of Common Stock, results in either the receipt of cash (or check) by
the Company or the receipt of irrevocable instructions to pay the aggregate
exercise price to the Company from the sales proceeds;

                        (iii) Provided that at the time of exercise the
Company's Common Stock is publicly traded and quoted regularly in the Wall
Street Journal, payment by delivery of already-owned shares of Common Stock,
held for the period required to avoid a charge to the Company's reported
earnings, and owned free and clear of any liens, claims, encumbrances or
security interests, which Common Stock shall be valued at its fair market value
on the date of exercise; or

                        (iv)  Payment by a combination of the methods of payment
permitted by subparagraph 3(b)(i) through 3(b)(iii) above.

      4.    WHOLE SHARES. This option may not be exercised for any number of
shares which would require the issuance of anything other than whole shares.

      5.    SECURITIES LAW COMPLIANCE. Notwithstanding anything to the contrary
contained herein, this option may not be exercised unless the shares issuable
upon exercise of this option are then registered under the Act or, if such
shares are not then so registered, the Company has determined that such exercise
and issuance would be exempt from the registration requirements of the Act.

      6.    TERM. The term of this option commences on           , the date of
grant and expires on        (the "Expiration Date," which date shall be no more
than ten (10) years from the date this option is granted), unless this option
expires sooner as set forth below or in the Plan. In no event may this option be
exercised on or after the Expiration Date. This option shall terminate prior to
the Expiration Date as follows: three (3) months after the termination of your
Continuous Status as an Employee, Director or Consultant with the Company or an
Affiliate of the Company for any reason or for no reason unless:

            (a)   such termination of Continuous Status as an Employee, Director
or Consultant is due to your permanent and total disability (within the meaning
of Section 422(c)(6) of the Code), in which event the option shall expire on the
earlier of the Expiration Date set forth above or twelve (12) months following
such termination of Continuous Status as

<PAGE>

an Employee, Director or Consultant; or

            (b)   such termination of Continuous Status as an Employee, Director
or Consultant is due to your death or your death occurs within three (3) months
following your termination for any other reason, in which event the option shall
expire on the earlier of the Expiration Date set forth above or eighteen (18)
months after your death; or

            (c)   during any part of such three (3) month period the option is
not exercisable solely because of the condition set forth in paragraph 5 above,
in which event the option shall not expire until the earlier of the Expiration
Date set forth above or until it shall have been exercisable for an aggregate
period of three (3) months after the termination of Continuous Status as an
Employee, Director or Consultant; or

            (d)   exercise of the option within three (3) months after
termination of your Continuous Status as an Employee, Director or Consultant
with the Company or with an Affiliate of the Company would result in liability
under section 16(b) of the Securities Exchange Act of 1934 (the "Exchange Act),
in which case the option will expire on the earlier of (i) the Expiration Date
set forth above, (ii) the tenth (10th) day after the last date upon which
exercise would result in such liability or (iii) six (6) months and ten (10)
days after the termination of your Continuous Status as an Employee, Director or
Consultant with the Company or an Affiliate of the Company.

      However, this option may be exercised following termination of Continuous
Status as an Employee, Director or Consultant only as to that number of shares
as to which it was exercisable on the date of termination of Continuous Status
as an Employee, Director or Consultant under the provisions of paragraph 2 of
this option.

      7.    EXERCISE.

            (a)   This option may be exercised, to the extent specified above,
by delivering a notice of exercise (in a form designated by the Company)
together with the exercise price to the Secretary of the Company, or to such
other person as the Company may designate, during regular business hours,
together with such additional documents as the Company may then require pursuant
to subsection 6(f) of the Plan.

            (b)   By exercising this option you agree that:

                        (i)   as a precondition to the completion of any
exercise of this option, the Company may require you to enter an arrangement
providing for the cash payment by you to the Company of any tax withholding
obligation of the Company arising by reason of: (1) the exercise of this option;
(2) the lapse of any substantial risk of forfeiture to which the shares are
subject at the time of exercise; or (3) the disposition of shares acquired upon
such exercise. You also agree that any exercise of this option has not been
completed and that the Company is under no obligation to issue any Common Stock
to you until such an

<PAGE>

arrangement is established or the Company's tax withholding obligations are
satisfied, as determined by the Company; and

                        (ii)  the Company (or a representative of the
underwriters) may, in connection with the first underwritten registration of the
offering of any securities of the Company under the Act, require that you not
sell or otherwise transfer or dispose of any shares of Common Stock or other
securities of the Company during such period (not to exceed one hundred eighty
(180) days) following the effective date (the "Effective Date") of the
registration statement of the Company filed under the Act as may be requested by
the Company or the representative of the underwriters. You further agree that
the Company may impose stop-transfer instructions with respect to securities
subject to the foregoing restrictions until the end of such period.

      8.    TRANSFERABILITY. This option is not transferable, except by will or
by the laws of descent and distribution, and is exercisable during your life
only by you. Notwithstanding the foregoing, by delivering written notice to the
Company, in a form satisfactory to the Company, you may designate a third party
who, in the event of your death, shall thereafter be entitled to exercise this
option.

      9.    OPTION NOT A SERVICE CONTRACT. This option is not an employment
contract and nothing in this option shall be deemed to create in any way
whatsoever any obligation on your part to continue in the employ of the Company,
or of the Company to continue your employment with the Company. In addition,
nothing in this option shall obligate the Company or any Affiliate of the
Company, or their respective shareholders, Board of Directors, officers, or
employees to continue any relationship which you might have as a Director or
Consultant for the Company or Affiliate of the Company.

      10.   NOTICES. Any notices provided for in this option or the Plan shall
be given in writing and shall be deemed effectively given upon receipt or, in
the case of notices delivered by the Company to you, five (5) days after deposit
in the United States mail, postage prepaid, addressed to you at the address
specified below or at such other address as you hereafter designate by written
notice to the Company.

<PAGE>

      11.   GOVERNING PLAN DOCUMENT. This option is subject to all the
provisions of the Plan, a copy of which is attached hereto and its provisions
are hereby made a part of this option, including without limitation the
provisions of Section 6 of the Plan relating to option provisions, and is
further subject to all interpretations, amendments, rules and regulations which
may from time to time be promulgated and adopted pursuant to the Plan. In the
event of any conflict between the provisions of this option and those of the
Plan, the provisions of the Plan shall control.

Dated the         day of       ,         .

                                           Very truly yours,

                                           _____________________________________
                                           Greg Hildebrand
                                           Director of Finance

                                           Duly authorized on behalf
                                           of the Board of Directors

ATTACHMENTS:

      Notice of Exercise

<PAGE>

                                                     Grant Date:
                                                     Number of Shares:
                                                     Exercise Price: $
                                                     Total Exercise Price: $

The undersigned:

      (a)   Acknowledges receipt of the foregoing option and the attachments
referenced therein and understands that all rights and liabilities with respect
to this option are set forth in the option and the Plan; and

      (b)   Acknowledges that as of the date of grant of this option, it sets
forth the entire understanding between the undersigned optionee and the Company
and its Affiliates regarding the acquisition of stock in the Company and
supersedes all prior oral and written agreements on that subject with the
exception of (i) the options previously granted and delivered to the undersigned
under stock option plans of the Company, and (ii) the following agreements only:

      NONE            _____________________________
                      (Initial)

      OTHER
                      _________________________________________
                      _________________________________________
                      _________________________________________

                                              __________________________________

                                              OPTIONEE

                                              Address:<PAGE>

                                                                    EXHIBIT 10.4

                       VOLTERRA SEMICONDUCTOR CORPORATION

                           2004 EQUITY INCENTIVE PLAN

                              ADOPTED: MAY 7, 2004
                 APPROVED BY STOCKHOLDERS: _______________, 2004
                          TERMINATION DATE: MAY 6, 2014

1.    PURPOSES.

      (a)   AMENDMENT AND RESTATEMENT. This Plan is a complete amendment and
restatement of the Company's 1996 Stock Option Plan that was previously adopted
on October 29, 1996 (the "PRIOR PLAN"). All outstanding awards granted under the
Prior Plan shall remain subject to the terms of the Prior Plan. All Stock Awards
granted subsequent to the effective date of this Plan shall be subject to the
terms of this Plan.

      (b)   ELIGIBLE STOCK AWARD RECIPIENTS. The persons eligible to receive
Stock Awards are Employees, Directors and Consultants.

      (c)   AVAILABLE STOCK AWARDS. The Plan provides for the grant of the
following Stock Awards: (i) Incentive Stock Options, (ii) Nonstatutory Stock
Options, (iii) Stock Purchase Awards, (iv) Stock Bonus Awards, (v) Stock
Appreciation Rights, (vi) Stock Unit Awards and (vii) Other Stock Awards.

      (d)   GENERAL PURPOSE. The Company, by means of the Plan, seeks to secure
and retain the services of the group of persons eligible to receive Stock
Awards, to provide incentives for such persons to exert maximum efforts for the
success of the Company and its Affiliates and to provide a means by which such
eligible recipients may be given an opportunity to benefit from increases in
value of the Common Stock through the granting of Stock Awards.

2.    DEFINITIONS.

      As used in the Plan, the following definitions shall apply to the
capitalized terms indicated below:

      (a)   "AFFILIATE" means any parent corporation or subsidiary corporation
of the Company, whether now or hereafter existing, as those terms are defined in
Sections 424(e) and (f), respectively, of the Code.

      (b)   "BOARD" means the Board of Directors of the Company.

      (c)   "CAPITALIZATION ADJUSTMENT" has the meaning ascribed to that term in
Section 11(a).

      (d)   "CHANGE IN CONTROL" means the occurrence, in a single transaction or
in a series of related transactions, of any one or more of the following events:

                                       1.

<PAGE>

            (i)   any Exchange Act Person becomes the Owner, directly or
indirectly, of securities of the Company representing more than fifty percent
(50%) of the combined voting power of the Company's then outstanding securities
other than by virtue of a merger, consolidation or similar transaction.
Notwithstanding the foregoing, a Change in Control shall not be deemed to occur
(A) on account of the acquisition of securities of the Company by an investor,
any affiliate thereof or any other Exchange Act Person from the Company in a
transaction or series of related transactions the primary purpose of which is to
obtain financing for the Company through the issuance of equity securities or
(B) solely because the level of Ownership held by any Exchange Act Person (the
"Subject Person") exceeds the designated percentage threshold of the outstanding
voting securities as a result of a repurchase or other acquisition of voting
securities by the Company reducing the number of shares outstanding, provided
that if a Change in Control would occur (but for the operation of this sentence)
as a result of the acquisition of voting securities by the Company, and after
such share acquisition, the Subject Person becomes the Owner of any additional
voting securities that, assuming the repurchase or other acquisition had not
occurred, increases the percentage of the then outstanding voting securities
Owned by the Subject Person over the designated percentage threshold, then a
Change in Control shall be deemed to occur;

            (ii)  there is consummated a merger, consolidation or similar
transaction involving (directly or indirectly) the Company and, immediately
after the consummation of such merger, consolidation or similar transaction, the
stockholders of the Company immediately prior thereto do not Own, directly or
indirectly, either (A) outstanding voting securities representing more than
fifty percent (50%) of the combined outstanding voting power of the surviving
Entity in such merger, consolidation or similar transaction or (B) more than
fifty percent (50%) of the combined outstanding voting power of the parent of
the surviving Entity in such merger, consolidation or similar transaction, in
each case in substantially the same proportions as their Ownership of the
outstanding voting securities of the Company immediately prior to such
transaction;

            (iii) the stockholders of the Company approve or the Board approves
a plan of complete dissolution or liquidation of the Company, or a complete
dissolution or liquidation of the Company shall otherwise occur;

            (iv)  there is consummated a sale, lease, license or other
disposition of all or substantially all of the consolidated assets of the
Company and its Subsidiaries, other than a sale, lease, license or other
disposition of all or substantially all of the consolidated assets of the
Company and its Subsidiaries to an Entity, more than fifty percent (50%) of the
combined voting power of the voting securities of which are Owned by
stockholders of the Company in substantially the same proportions as their
Ownership of the outstanding voting securities of the Company immediately prior
to such sale, lease, license or other disposition; or

            (v)   individuals who, on the date this Plan is adopted by the
Board, are members of the Board (the "Incumbent Board") cease for any reason to
constitute at least a majority of the members of the Board; provided, however,
that if the appointment or election (or nomination for election) of any new
Board member was approved or recommended by a majority vote of the members of
the Incumbent Board then still in office, such new member shall, for purposes of
this Plan, be considered as a member of the Incumbent Board.

                                       2.

<PAGE>

      The term Change in Control shall not include a sale of assets, merger or
other transaction effected exclusively for the purpose of changing the domicile
of the Company.

      Notwithstanding the foregoing or any other provision of this Plan, the
definition of Change in Control (or any analogous term) in an individual written
agreement between the Company or any Affiliate and the Participant shall
supersede the foregoing definition with respect to Stock Awards subject to such
agreement (it being understood, however, that if no definition of Change in
Control or any analogous term is set forth in such an individual written
agreement, the foregoing definition shall apply).

      (e)   "CODE" means the Internal Revenue Code of 1986, as amended.

      (f)   "COMMITTEE" means a committee of one (1) or more members of the
Board appointed by the Board in accordance with Section 3(c).

      (g)   "COMMON STOCK" means the common stock of the Company.

      (h)   "COMPANY" means Volterra Semiconductor Corporation, a Delaware
corporation.

      (i)   "CONSULTANT" means any person, including an advisor, who (i) is
engaged by the Company or an Affiliate to render consulting or advisory services
and is compensated for such services or (ii) is serving as a member of the Board
of Directors of an Affiliate and is compensated for such services. However,
service solely as a Director, or payment of a fee for such services, shall not
cause a Director to be considered a "Consultant" for purposes of the Plan.

      (j)   "CONTINUOUS SERVICE" means that the Participant's service with the
Company or an Affiliate, whether as an Employee, Director or Consultant, is not
interrupted or terminated. A change in the capacity in which the Participant
renders service to the Company or an Affiliate as an Employee, Consultant or
Director or a change in the entity for which the Participant renders such
service, provided that there is no interruption or termination of the
Participant's service with the Company or an Affiliate, shall not terminate a
Participant's Continuous Service. For example, a change in status from an
employee of the Company to a consultant to an Affiliate or to a Director shall
not constitute an interruption of Continuous Service. The Board or the chief
executive officer of the Company, in that party's sole discretion, may determine
whether Continuous Service shall be considered interrupted in the case of any
leave of absence approved by that party, including sick leave, military leave or
any other personal leave. Notwithstanding the foregoing, a leave of absence
shall be treated as Continuous Service for purposes of vesting in a Stock Award
only to such extent as may be provided in the Company's leave of absence policy
or in the written terms of the Participant's leave of absence.

      (k)   "CORPORATE TRANSACTION" means the occurrence, in a single
transaction or in a series of related transactions, of any one or more of the
following events:

            (i)   a sale or other disposition of all or substantially all, as
determined by the Board in its sole discretion, of the consolidated assets of
the Company and its Subsidiaries;

            (ii)  a sale or other disposition of at least ninety percent (90%)
of the outstanding securities of the Company;

                                       3.

<PAGE>

            (iii) a merger, consolidation or similar transaction following which
the Company is not the surviving corporation; or

            (iv)  a merger, consolidation or similar transaction following which
the Company is the surviving corporation but the shares of Common Stock
outstanding immediately preceding the merger, consolidation or similar
transaction are converted or exchanged by virtue of the merger, consolidation or
similar transaction into other property, whether in the form of securities, cash
or otherwise.

      (l)   "COVERED EMPLOYEE" means the chief executive officer and the four
(4) other highest compensated officers of the Company for whom total
compensation is required to be reported to stockholders under the Exchange Act,
as determined for purposes of Section 162(m) of the Code.

      (m)   "DILUTED SHARES OUTSTANDING" means, as of any date, (i) the number
of outstanding shares of Common Stock of the Company on such Calculation Date
(as defined in Section 4(a) herein), plus (ii) the number of shares of Common
Stock issuable upon such Calculation Date assuming the conversion of all
outstanding Preferred Stock and convertible notes, plus (iii) the additional
number of dilutive Common Stock equivalent shares outstanding as the result of
any options or warrants outstanding during the fiscal year, calculated using the
treasury stock method.

      (n)   "DIRECTOR" means a member of the Board.

      (o)   "DISABILITY" means the permanent and total disability of a person
within the meaning of Section 22(e)(3) of the Code.

      (p)   "EMPLOYEE" means any person employed by the Company or an Affiliate.
However, service solely as a Director, or payment of a fee for such services,
shall not cause a Director to be considered an "Employee" for purposes of the
Plan.

      (q)   "ENTITY" means a corporation, partnership or other entity.

      (r)   "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
amended.

      (s)   "EXCHANGE ACT PERSON" means any natural person, Entity or "group"
(within the meaning of Section 13(d) or 14(d) of the Exchange Act), except that
"Exchange Act Person" shall not include (i) the Company or any Subsidiary of the
Company, (ii) any employee benefit plan of the Company or any Subsidiary of the
Company or any trustee or other fiduciary holding securities under an employee
benefit plan of the Company or any Subsidiary of the Company, (iii) an
underwriter temporarily holding securities pursuant to an offering of such
securities, (iv) an Entity Owned, directly or indirectly, by the stockholders of
the Company in substantially the same proportions as their Ownership of stock of
the Company; or (v) any natural person, Entity or "group" (within the meaning of
Section 13(d) or 14(d) of the Exchange Act) that, as of the effective date of
the Plan as set forth in Section 14, is the Owner, directly or indirectly, of
securities of the Company representing more than fifty percent (50%) of the
combined voting power of the Company's then outstanding securities.

                                       4.

<PAGE>

      (t)   "FAIR MARKET VALUE" means, as of any date, the value of the Common
Stock determined as follows:

            (i)   If the Common Stock is listed on any established stock
exchange or traded on the Nasdaq National Market or the Nasdaq SmallCap Market,
the Fair Market Value of a share of Common Stock shall be the closing sales
price for such stock (or the closing bid, if no sales were reported) as quoted
on such exchange or market (or the exchange or market with the greatest volume
of trading in the Common Stock) on the last market trading day prior to the day
of determination, as reported in The Wall Street Journal or such other source as
the Board deems reliable.

            (ii)  In the absence of such markets for the Common Stock, the Fair
Market Value shall be determined by the Board in good faith.

      (u)   "INCENTIVE STOCK OPTION" means an Option intended to qualify as an
incentive stock option within the meaning of Section 422 of the Code and the
regulations promulgated thereunder.

      (v)   "IPO DATE" means the first day that the Common Stock is publicly
traded.

      (w)   "NON-EMPLOYEE DIRECTOR" means a Director who either (i) is not a
current employee or officer of the Company or an Affiliate, does not receive
compensation, either directly or indirectly, from the Company or an Affiliate
for services rendered as a consultant or in any capacity other than as a
Director (except for an amount as to which disclosure would not be required
under Item 404(a) of Regulation S-K promulgated pursuant to the Securities Act
("Regulation S-K")), does not possess an interest in any other transaction for
which disclosure would be required under Item 404(a) of Regulation S-K, and is
not engaged in a business relationship for which disclosure would be required
pursuant to Item 404(b) of Regulation S-K; or (ii) is otherwise considered a
"non-employee director" for purposes of Rule 16b-3.

      (x)   "NONSTATUTORY STOCK OPTION" means an Option not intended to qualify
as an Incentive Stock Option.

      (y)   "OFFICER" means a person who is an officer of the Company within the
meaning of Section 16 of the Exchange Act and the rules and regulations
promulgated thereunder.

      (z)   "OPTION" means an Incentive Stock Option or a Nonstatutory Stock
Option to purchase shares of Common Stock granted pursuant to the Plan.

      (aa)  "OPTION AGREEMENT" means a written agreement between the Company and
an Optionholder evidencing the terms and conditions of an Option grant. Each
Option Agreement shall be subject to the terms and conditions of the Plan.

      (bb)  "OPTIONHOLDER" means a person to whom an Option is granted pursuant
to the Plan or, if applicable, such other person who holds an outstanding
Option.

      (cc)  "OTHER STOCK AWARD" means an award based in whole or in part by
reference to the Common Stock which is granted pursuant to the terms and
conditions of Section 7(e).

                                       5.

<PAGE>

      (dd)  "OTHER STOCK AWARD AGREEMENT" means a written agreement between the
Company and a holder of an Other Stock Award evidencing the terms and conditions
of an Other Stock Award grant. Each Other Stock Award Agreement shall be subject
to the terms and conditions of the Plan.

      (ee)  "OUTSIDE DIRECTOR" means a Director who either (i) is not a current
employee of the Company or an "affiliated corporation" (within the meaning of
Treasury Regulations promulgated under Section 162(m) of the Code), is not a
former employee of the Company or an "affiliated corporation" who receives
compensation for prior services (other than benefits under a tax-qualified
retirement plan) during the taxable year, has not been an officer of the Company
or an "affiliated corporation", and does not receive remuneration from the
Company or an "affiliated corporation," either directly or indirectly, in any
capacity other than as a Director or (ii) is otherwise considered an "outside
director" for purposes of Section 162(m) of the Code.

      (ff)  "OWN," "OWNED," "OWNER," "OWNERSHIP" A person or Entity shall be
deemed to "Own," to have "Owned," to be the "Owner" of, or to have acquired
"Ownership" of securities if such person or Entity, directly or indirectly,
through any contract, arrangement, understanding, relationship or otherwise, has
or shares voting power, which includes the power to vote or to direct the
voting, with respect to such securities.

      (gg)  "PARTICIPANT" means a person to whom a Stock Award is granted
pursuant to the Plan or, if applicable, such other person who holds an
outstanding Stock Award.

      (hh)  "PLAN" means this Volterra Semiconductor Corporation 2004 Equity
Incentive Plan.

      (ii)  "RULE 16b-3" means Rule 16b-3 promulgated under the Exchange Act or
any successor to Rule 16b-3, as in effect from time to time.

      (jj)  "SECURITIES ACT" means the Securities Act of 1933, as amended.

      (kk)  "STOCK APPRECIATION RIGHT" means a right to receive the appreciation
on Common Stock that is granted pursuant to the terms and conditions of Section
7(d).

      (ll)  "STOCK APPRECIATION RIGHT AGREEMENT" means a written agreement
between the Company and a holder of a Stock Appreciation Right evidencing the
terms and conditions of a Stock Appreciation Right grant. Each Stock
Appreciation Right Agreement shall be subject to the terms and conditions of the
Plan.

      (mm)  "STOCK AWARD" means any right granted under the Plan, including an
Option, a Stock Purchase Award, Stock Bonus Award, a Stock Appreciation Right, a
Stock Unit Award or any Other Stock Award.

      (nn)  "STOCK AWARD AGREEMENT" means a written agreement between the
Company and a Participant evidencing the terms and conditions of a Stock Award
grant. Each Stock Award Agreement shall be subject to the terms and conditions
of the Plan.

                                       6.

<PAGE>

      (oo)  "STOCK BONUS AWARD" means an award of shares of Common Stock that is
granted pursuant to the terms and conditions of Section 7(b).

      (pp)  "STOCK BONUS AWARD AGREEMENT" means a written agreement between the
Company and a holder of a Stock Bonus Award evidencing the terms and conditions
of a Stock Bonus Award grant. Each Stock Bonus Award Agreement shall be subject
to the terms and conditions of the Plan.

      (qq)  "STOCK PURCHASE AWARD" means an award of shares of Common Stock that
is granted pursuant to the terms and conditions of Section 7(a).

      (rr)  "STOCK PURCHASE AWARD AGREEMENT" means a written agreement between
the Company and a holder of a Stock Purchase Award evidencing the terms and
conditions of a Stock Purchase Award grant. Each Stock Purchase Award Agreement
shall be subject to the terms and conditions of the Plan.

      (ss)  "STOCK UNIT AWARD" means a right to receive shares of Common Stock
that is granted pursuant to the terms and conditions of Section 7(c).

      (tt)  "STOCK UNIT AWARD AGREEMENT" means a written agreement between the
Company and a holder of a Stock Unit Award evidencing the terms and conditions
of a Stock Unit Award grant. Each Stock Unit Award Agreement shall be subject to
the terms and conditions of the Plan.

      (uu)  "SUBSIDIARY" means, with respect to the Company, (i) any corporation
of which more than fifty percent (50%) of the outstanding capital stock having
ordinary voting power to elect a majority of the board of directors of such
corporation (irrespective of whether, at the time, stock of any other class or
classes of such corporation shall have or might have voting power by reason of
the happening of any contingency) is at the time, directly or indirectly, Owned
by the Company, and (ii) any partnership in which the Company has a direct or
indirect interest (whether in the form of voting or participation in profits or
capital contribution) of more than fifty percent (50%).

      (vv)  "TEN PERCENT STOCKHOLDER" means a person who Owns (or is deemed to
Own pursuant to Section 424(d) of the Code) stock possessing more than ten
percent (10%) of the total combined voting power of all classes of stock of the
Company or of any of its Affiliates.

3.    ADMINISTRATION.

      (a)   ADMINISTRATION BY BOARD. The Board shall administer the Plan unless
and until the Board delegates administration of the Plan to a Committee, as
provided in Section 3(c).

      (b)   POWERS OF BOARD. The Board shall have the power, subject to, and
within the limitations of, the express provisions of the Plan:

            (i)   To determine from time to time which of the persons eligible
under the Plan shall be granted Stock Awards; when and how each Stock Award
shall be granted; what type or combination of types of Stock Award shall be
granted; the provisions of each Stock

                                       7.

<PAGE>

Award granted (which need not be identical), including the time or times when a
person shall be permitted to receive Common Stock pursuant to a Stock Award; and
the number of shares of Common Stock with respect to which a Stock Award shall
be granted to each such person.

            (ii)  To construe and interpret the Plan and Stock Awards granted
under it, and to establish, amend and revoke rules and regulations for its
administration. The Board, in the exercise of this power, may correct any
defect, omission or inconsistency in the Plan or in any Stock Award Agreement,
in a manner and to the extent it shall deem necessary or expedient to make the
Plan fully effective.

            (iii) To effect, at any time and from time to time, with the consent
of any adversely affected Optionholder, (1) the reduction of the exercise price
of any outstanding Option under the Plan, (2) the cancellation of any
outstanding Option under the Plan and the grant in substitution therefor of (A)
a new Option under the Plan or another equity plan of the Company covering the
same or a different number of shares of Common Stock, (B) a Stock Purchase
Award, (C) a Stock Bonus Award, (D) a Stock Appreciation Right, (E) a Stock Unit
Award, (F) an Other Stock Award, (G) cash and/or (H) other valuable
consideration (as determined by the Board, in its sole discretion), or (3) any
other action that is treated as a repricing under generally accepted accounting
principles.

            (iv)  To amend the Plan or a Stock Award as provided in Section 12.

            (v)   To terminate or suspend the Plan as provided in Section 13.

            (vi)  Generally, to exercise such powers and to perform such acts as
the Board deems necessary or expedient to promote the best interests of the
Company and that are not in conflict with the provisions of the Plan.

            (vii) To adopt such procedures and sub-plans as are necessary or
appropriate to permit participation in the Plan by Employees who are foreign
nationals or employed outside the United States.

      (c)   DELEGATION TO COMMITTEE.

            (i)   GENERAL. The Board may delegate some or all of the
administration of the Plan to a Committee or Committees of one (1) or more
members of the Board, and the term "COMMITTEE" shall apply to any person or
persons to whom such authority has been delegated. If administration is
delegated to a Committee, the Committee shall have, in connection with the
administration of the Plan, the powers theretofore possessed by the Board that
have been delegated to the Committee, including the power to delegate to a
subcommittee any of the administrative powers the Committee is authorized to
exercise (and references in this Plan to the Board shall thereafter be to the
Committee or subcommittee), subject, however, to such resolutions, not
inconsistent with the provisions of the Plan, as may be adopted from time to
time by the Board. The Board may retain the authority to concurrently administer
the Plan with the Committee and may, at any time, revest in the Board some or
all of the powers previously delegated.

                                       8.

<PAGE>

            (ii)  SECTION 162(m) AND RULE 16B-3 COMPLIANCE. In the sole
discretion of the Board, the Committee may consist solely of two or more Outside
Directors, in accordance with Section 162(m) of the Code, and/or solely of two
or more Non-Employee Directors, in accordance with Rule 16b-3. In addition, the
Board or the Committee, in its sole discretion, may (1) delegate to a committee
of one or more members of the Board who need not be Outside Directors the
authority to grant Stock Awards to eligible persons who are either (a) not then
Covered Employees and are not expected to be Covered Employees at the time of
recognition of income resulting from such Stock Award, or (b) not persons with
respect to whom the Company wishes to comply with Section 162(m) of the Code,
and/or (2) delegate to a committee of one or more members of the Board who need
not be Non-Employee Directors the authority to grant Stock Awards to eligible
persons who are not then subject to Section 16 of the Exchange Act.

      (d)   DELEGATION TO AN OFFICER. The Board may delegate to one or more
Officers of the Company the authority to do one or both of the following (i)
designate Officers and Employees of the Company or any of its Subsidiaries to be
recipients of Stock Awards and (ii) determine the number of shares of Common
Stock to be subject to such Stock Awards granted to such Officers and Employees
of the Company; provided, however, that the Board resolutions regarding such
delegation shall specify the total number of shares of Common Stock that may be
subject to the Stock Awards granted by such Officer and that such Officer may
not grant a Stock Award to himself or herself. Notwithstanding anything to the
contrary in this Section 3(d), the Board may not delegate to an Officer
authority to determine the Fair Market Value of the Common Stock pursuant to
Section 2(t)(ii) above.

      (e)   EFFECT OF BOARD'S DECISION. All determinations, interpretations and
constructions made by the Board in good faith shall not be subject to review by
any person and shall be final, binding and conclusive on all persons.

4.    SHARES SUBJECT TO THE PLAN.

      (a)   SHARE RESERVE. Subject to the provisions of Section 11(a) relating
to Capitalization Adjustments, the Common Stock that may be issued pursuant to
Stock Awards shall not exceed in the aggregate sixteen million nine hundred
sixty-seven thousand five hundred (16,967,500) shares of Common Stock, plus an
annual increase to be added on December 31st of each year, commencing on
December 31, 2004 and ending on December 31, 2013 (each such day, a "Calculation
Date"), equal to five percent (5%) of the Diluted Shares Outstanding on each
such Calculation Date (rounded down to the nearest whole share). Notwithstanding
the foregoing, the Board may act, prior to the last day of any fiscal year of
the Company, to increase the share reserve by such number of shares of Common
Stock as the Board shall determine, which number shall be less than the amount
determined in the prior sentence.

      (b)   REVERSION OF SHARES TO THE SHARE RESERVE. If any Stock Award shall
for any reason expire or otherwise terminate, in whole or in part, without
having been exercised in full, or if any shares of Common Stock issued to a
Participant pursuant to a Stock Award are forfeited to or repurchased by the
Company, including, but not limited to, any repurchase or forfeiture caused by
the failure to meet a contingency or condition required for the vesting of such
shares, then the shares of Common Stock not issued under such Stock Award, or
forfeited to or repurchased by the Company, shall revert to and again become
available for issuance under the

                                       9.

<PAGE>

Plan. If any shares subject to a Stock Award are not delivered to a Participant
because such shares are withheld for the payment of taxes or the Stock Award is
exercised through a reduction of shares subject to the Stock Award (i.e., "net
exercised"), the number of shares that are not delivered to the Participant
shall remain available for issuance under the Plan. If the exercise price of any
Stock Award is satisfied by tendering shares of Common Stock held by the
Participant (either by actual delivery or attestation), then the number of
shares so tendered shall remain available for issuance under the Plan.
Notwithstanding anything to the contrary in this Section 4(b), subject to the
provisions of Section 11(a) relating to Capitalization Adjustments the aggregate
maximum number of shares of Common Stock that may be issued pursuant to the
exercise of Incentive Stock Options shall be sixteen million nine hundred
sixty-seven thousand five hundred (16,967,500) shares of Common Stock.

      (c)   SOURCE OF SHARES. The shares of Common Stock subject to the Plan may
be unissued shares or reacquired shares, bought on the market or otherwise.

5.    ELIGIBILITY.

      (a)   ELIGIBILITY FOR SPECIFIC STOCK AWARDS. Incentive Stock Options may
be granted only to Employees. Stock Awards other than Incentive Stock Options
may be granted to Employees, Directors and Consultants.

      (b)   TEN PERCENT STOCKHOLDERS. A Ten Percent Stockholder shall not be
granted an Incentive Stock Option unless the exercise price of such Option is at
least one hundred ten percent (110%) of the Fair Market Value of the Common
Stock on the date of grant and the Option is not exercisable after the
expiration of five (5) years from the date of grant.

      (c)   CONSULTANTS. A Consultant shall not be eligible for the grant of a
Stock Award if, at the time of grant, a Form S-8 Registration Statement under
the Securities Act ("FORM S-8") is not available to register either the offer or
the sale of the Company's securities to such Consultant because of the nature of
the services that the Consultant is providing to the Company, because the
Consultant is not a natural person, or because of any other rule governing the
use of Form S-8.

6.    OPTION PROVISIONS.

      Each Option shall be in such form and shall contain such terms and
conditions as the Board shall deem appropriate. All Options shall be separately
designated Incentive Stock Options or Nonstatutory Stock Options at the time of
grant, and, if certificates are issued, a separate certificate or certificates
shall be issued for shares of Common Stock purchased on exercise of each type of
Option. The provisions of separate Options need not be identical, but each
Option shall include (through incorporation of provisions hereof by reference in
the Option or otherwise) the substance of each of the following provisions:

      (a)   TERM. The Board shall determine the term of an Option; provided
however that, Subject to the provisions of Section 5(b) regarding Ten Percent
Stockholders, no Incentive Stock Option shall be exercisable after the
expiration of ten (10) years from the date on which it was granted.

                                      10.

<PAGE>

      (b)   EXERCISE PRICE OF AN INCENTIVE STOCK OPTION. Subject to the
provisions of Section 5(b) regarding Ten Percent Stockholders, the exercise
price of each Incentive Stock Option shall be not less than one hundred percent
(100%) of the Fair Market Value of the Common Stock subject to the Option on the
date the Option is granted. Notwithstanding the foregoing, an Incentive Stock
Option may be granted with an exercise price lower than that set forth in the
preceding sentence if such Option is granted pursuant to an assumption or
substitution for another option in a manner satisfying the provisions of Section
424(a) of the Code.

      (c)   EXERCISE PRICE OF A NONSTATUTORY STOCK OPTION. The exercise price of
each Nonstatutory Stock Option shall be not less than fifty percent (50%) of the
Fair Market Value of the Common Stock subject to the Option on the date the
Option is granted. Notwithstanding the foregoing, a Nonstatutory Stock Option
may be granted with an exercise price lower than that set forth in the preceding
sentence if such Option is granted pursuant to an assumption or substitution for
another option in a manner consistent with the provisions of Section 424(a) of
the Code.

      (d)   CONSIDERATION. The purchase price of Common Stock acquired pursuant
to an Option shall be paid, to the extent permitted by applicable statutes and
regulations, either (i) in cash at the time the Option is exercised, (ii)
pursuant to a program developed under Regulation T as promulgated by the Federal
Reserve Board that, prior to the issuance of Common Stock, results in either the
receipt of cash (or check) by the Company or the receipt of irrevocable
instructions to pay the aggregate exercise price to the Company from the sales
proceeds, or (iii) at the sole discretion of the Board at the time of the grant
of the Option (or subsequently in the case of a Nonstatutory Stock Option) (1)
by delivery to the Company (either by actual delivery or attestation) of other
Common Stock at the time the Option is exercised, (2) by a "net exercise" of the
Option (as further described below), (3) according to a deferred payment or
other similar arrangement with the Optionholder, or (4) in any other form of
legal consideration that may be acceptable to the Board. Unless otherwise
specifically provided in the Option, the purchase price of Common Stock acquired
pursuant to an Option that is paid by delivery to the Company of other Common
Stock acquired, directly or indirectly from the Company, shall be paid only by
shares of the Common Stock of the Company that have been held for more than six
(6) months (or such longer or shorter period of time required to avoid a charge
to earnings for financial accounting purposes). At any time that the Company is
incorporated in Delaware, payment of the Common Stock's "par value," as defined
in the Delaware General Corporation Law, shall not be made by deferred payment.

      In the case of any deferred payment arrangement, interest shall be
compounded at least annually and shall be charged at the minimum rate of
interest necessary to avoid (1) the treatment as interest, under any applicable
provisions of the Code, of any amounts other than amounts stated to be interest
under the deferred payment arrangement and (2) the treatment of the Option as a
variable award for financial accounting purposes.

      In the case of a "net exercise" of an Option, the Company will not require
a payment of the exercise price of the Option from the Participant but will
reduce the number of shares of Common Stock issued upon the exercise by the
largest number of whole shares that has a Fair Market Value that does not exceed
the aggregate exercise price. With respect to any remaining

                                      11.

<PAGE>

balance of the aggregate exercise price, the Company shall accept a cash payment
from the Participant. Shares of Common Stock will no longer be outstanding under
an Option (and, therefore, will not thereafter be exercisable) following the
exercise of such Option to the extent of (i) shares used to pay the exercise
price of an Option under a "net exercise", (ii) shares actually delivered to the
Participant as a result of such exercise and (iii) shares withheld for purposes
of tax withholding.

      (e)   TRANSFERABILITY OF AN INCENTIVE STOCK OPTION. An Incentive Stock
Option shall not be transferable except by will or by the laws of descent and
distribution and shall be exercisable during the lifetime of the Optionholder
only by the Optionholder. Notwithstanding the foregoing, the Optionholder may,
by delivering written notice to the Company, in a form provided by or otherwise
satisfactory to the Company, designate a third party who, in the event of the
death of the Optionholder, shall thereafter be entitled to exercise the Option.

      (f)   TRANSFERABILITY OF A NONSTATUTORY STOCK OPTION. A Nonstatutory Stock
Option shall be transferable to the extent provided in the Option Agreement. If
the Nonstatutory Stock Option does not provide for transferability, then the
Nonstatutory Stock Option shall not be transferable except by will or by the
laws of descent and distribution and shall be exercisable during the lifetime of
the Optionholder only by the Optionholder. Notwithstanding the foregoing, the
Optionholder may, by delivering written notice to the Company, in a form
provided by or otherwise satisfactory to the Company, designate a third party
who, in the event of the death of the Optionholder, shall thereafter be entitled
to exercise the Option.

      (g)   VESTING GENERALLY. The total number of shares of Common Stock
subject to an Option may vest and therefore become exercisable in periodic
installments that may be equal. The Option may be subject to such other terms
and conditions on the time or times when it may be exercised (which may be based
on performance or other criteria) as the Board may deem appropriate. The vesting
provisions of individual Options may vary. The provisions of this Section 6(g)
are subject to any Option provisions governing the minimum number of shares of
Common Stock as to which an Option may be exercised.

      (h)   TERMINATION OF CONTINUOUS SERVICE. In the event that an
Optionholder's Continuous Service terminates (other than upon the Optionholder's
death or Disability or upon a Change in Control), the Optionholder may exercise
his or her Option (to the extent that the Optionholder was entitled to exercise
such Option as of the date of termination of Continuous Service) but only within
such period of time ending on the earlier of (i) the expiration of the term of
the Option as set forth in the Option Agreement or (ii) the date three (3)
months following the termination of the Optionholder's Continuous Service (or
such longer or shorter period specified in the Option Agreement). If, after
termination of Continuous Service, the Optionholder does not exercise his or her
Option within the time specified herein or in the Option Agreement (as
applicable), the Option shall terminate.

      (i)   EXTENSION OF TERMINATION DATE. An Optionholder's Option Agreement
may provide that if the exercise of the Option following the termination of the
Optionholder's Continuous Service (other than upon the Optionholder's death or
Disability or upon a Change in Control) would be prohibited at any time solely
because the issuance of shares of Common Stock would violate the registration
requirements under the Securities Act, then the Option shall

                                      12.

<PAGE>

terminate on the earlier of (i) the expiration of the term of the Option set
forth in the Option Agreement or (ii) the expiration of a period of three (3)
months after the termination of the Optionholder's Continuous Service during
which the exercise of the Option would not be in violation of such registration
requirements.

      (j)   DISABILITY OF OPTIONHOLDER. In the event that an Optionholder's
Continuous Service terminates as a result of the Optionholder's Disability, the
Optionholder may exercise his or her Option (to the extent that the Optionholder
was entitled to exercise such Option as of the date of termination of Continuous
Service), but only within such period of time ending on the earlier of (i) the
expiration of the term of the Option as set forth in the Option Agreement or
(ii) the date twelve (12) months following such termination of Continuous
Service (or such longer or shorter period specified in the Option Agreement).
If, after termination of Continuous Service, the Optionholder does not exercise
his or her Option within the time specified herein or in the Option Agreement
(as applicable), the Option shall terminate.

      (k)   DEATH OF OPTIONHOLDER. In the event that (i) an Optionholder's
Continuous Service terminates as a result of the Optionholder's death or (ii)
the Optionholder dies within the period (if any) specified in the Option
Agreement after the termination of the Optionholder's Continuous Service, then
the Option may be exercised (to the extent the Optionholder was entitled to
exercise such Option as of the date of death) by the Optionholder's estate, by a
person who acquired the right to exercise the Option by bequest or inheritance
or by a person designated to exercise the option upon the Optionholder's death
pursuant to Section 6(e) or 6(f), but only within the period ending on the
earlier of (i) the expiration of the term of such Option as set forth in the
Option Agreement or (ii) the date eighteen (18) months following the date of
death (or such longer or shorter period specified in the Option Agreement). If,
after the Optionholder's death, the Option is not exercised within the time
specified herein or in the Option Agreement (as applicable), the Option shall
terminate.

      (l)   TERMINATION UPON CHANGE IN CONTROL. In the event that an
Optionholder's Continuous Service terminates as of, or within twelve (12) months
following a Change in Control, the Optionholder may exercise his or her Option
(to the extent that the Optionholder was entitled to exercise such Option as of
the date of termination of Continuous Service) within such period of time ending
on the earlier of (i) the expiration of the term of the Option as set forth in
the Option Agreement or (ii) the date twelve (12) months following the
termination of the Optionholder's Continuous Service (or such longer or shorter
period specified in the Option Agreement). If, after termination of Continuous
Service, the Optionholder does not exercise his or her Option within the time
specified herein or in the Option Agreement (as applicable), the Option shall
terminate.

      (m)   EARLY EXERCISE. The Option may include a provision whereby the
Optionholder may elect at any time before the Optionholder's Continuous Service
terminates to exercise the Option as to any part or all of the shares of Common
Stock subject to the Option prior to the full vesting of the Option. Any
unvested shares of Common Stock so purchased may be subject to a repurchase
option in favor of the Company or to any other restriction the Board determines
to be appropriate. The Company shall not be required to exercise its repurchase
option until at least six (6) months (or such longer or shorter period of time
required to avoid a charge to earnings for

                                      13.

<PAGE>

financial accounting purposes) have elapsed following exercise of the Option
unless the Board otherwise specifically provides in the Option.

7.    PROVISIONS OF STOCK AWARDS OTHER THAN OPTIONS.

      (a)   STOCK PURCHASE AWARDS. Each Stock Purchase Award Agreement shall be
in such form and shall contain such terms and conditions as the Board shall deem
appropriate. At the Board's election, shares of Common Stock may be (i) held in
book entry form subject to the Company's instructions until any restrictions
relating to the Stock Purchase Award lapse; or (ii) evidenced by a certificate,
which certificate shall be held in such form and manner as determined by the
Board. The terms and conditions of Stock Purchase Award Agreements may change
from time to time, and the terms and conditions of separate Stock Purchase Award
Agreements need not be identical, provided, however, that each Stock Purchase
Award Agreement shall include (through incorporation of the provisions hereof by
reference in the agreement or otherwise) the substance of each of the following
provisions:

            (i)   PURCHASE PRICE. At the time of the grant of a Stock Purchase
Award, the Board will determine the price to be paid by the Participant for each
share subject to the Stock Purchase Award. To the extent required by applicable
law, the price to be paid by the Participant for each share of the Stock
Purchase Award will not be less than the par value of a share of Common Stock.

            (ii)  CONSIDERATION. At the time of the grant of a Stock Purchase
Award, the Board will determine the consideration permissible for the payment of
the purchase price of the Stock Purchase Award. The purchase price of Common
Stock acquired pursuant to the Stock Purchase Award shall be paid either: (i) in
cash at the time of purchase, (ii) at the discretion of the Board, according to
a deferred payment or other similar arrangement with the Participant, (iii) by
past services rendered to the Company, or (iv) in any other form of legal
consideration that may be acceptable to the Board and permissible under the
Delaware General Corporation Law; provided, however, that at any time that the
Company is incorporated in Delaware, the Common Stock's "par value," as defined
in the Delaware General Corporation Law, shall not be paid by deferred payment
and must be paid in a form of consideration that is permissible under the
Delaware Corporation Law.

            (iii) VESTING. Shares of Common Stock acquired under a Stock
Purchase Award may be subject to a share repurchase right or option in favor of
the Company in accordance with a vesting schedule to be determined by the Board.

            (iv)  TERMINATION OF PARTICIPANT'S CONTINUOUS SERVICE. In the event
that a Participant's Continuous Service terminates, the Company shall have the
right, but not the obligation, to repurchase or otherwise reacquire, any or all
of the shares of Common Stock held by the Participant that have not vested as of
the date of termination under the terms of the Stock Purchase Award Agreement.
At the Board's election, the repurchase right may be at the least of: (i) the
Fair Market Value on the relevant date or (ii) the Participant's original cost.
The Company shall not be required to exercise its repurchase option until at
least six (6) months (or such longer or shorter period of time required to avoid
a charge to earnings for financial

                                      14.

<PAGE>

accounting purposes) have elapsed following the purchase of the restricted stock
unless otherwise determined by the Board or provided in the Stock Purchase Award
Agreement.

            (v)   TRANSFERABILITY. Rights to purchase or receive shares of
Common Stock granted under a Stock Purchase Award shall be transferable by the
Participant only upon such terms and conditions as are set forth in the Stock
Purchase Award Agreement, as the Board shall determine in its sole discretion,
and so long as Common Stock awarded under the Stock Purchase Award remains
subject to the terms of the Stock Purchase Award Agreement.

      (b)   STOCK BONUS AWARDS. Each Stock Bonus Award Agreement shall be in
such form and shall contain such terms and conditions as the Board shall deem
appropriate. At the Board's election, shares of Common Stock may be (i) held in
book entry form subject to the Company's instructions until any restrictions
relating to the Stock Bonus Award lapse; or (ii) evidenced by a certificate,
which certificate shall be held in such form and manner as determined by the
Board. The terms and conditions of Stock Bonus Award Agreements may change from
time to time, and the terms and conditions of separate Stock Bonus Award
Agreements need not be identical, but each Stock Bonus Award Agreement shall
include (through incorporation of provisions hereof by reference in the
agreement or otherwise) the substance of each of the following provisions:

            (i)   CONSIDERATION. A Stock Bonus Award may be awarded in
consideration for past services actually rendered to the Company or an
Affiliate.

            (ii)  VESTING. Shares of Common Stock awarded under the Stock Bonus
Award Agreement may be subject to forfeiture to the Company in accordance with a
vesting schedule to be determined by the Board.

            (iii) TERMINATION OF PARTICIPANT'S CONTINUOUS SERVICE. In the event
a Participant's Continuous Service terminates, the Company may receive, through
a forfeiture condition, any or all of the shares of Common Stock held by the
Participant that have not vested as of the date of termination of Continuous
Service under the terms of the Stock Bonus Award Agreement.

            (iv)  TRANSFERABILITY. Rights to acquire shares of Common Stock
under the Stock Bonus Award Agreement shall be transferable by the Participant
only upon such terms and conditions as are set forth in the Stock Bonus Award
Agreement, as the Board shall determine in its sole discretion, so long as
Common Stock awarded under the Stock Bonus Award Agreement remains subject to
the terms of the Stock Bonus Award Agreement.

      (c)   STOCK UNIT AWARDS. Each Stock Unit Award Agreement shall be in such
form and shall contain such terms and conditions as the Board shall deem
appropriate. The terms and conditions of Stock Unit Award Agreements may change
from time to time, and the terms and conditions of separate Stock Unit Award
Agreements need not be identical, provided, however, that each Stock Unit Award
Agreement shall include (through incorporation of the provisions hereof by
reference in the agreement or otherwise) the substance of each of the following
provisions:

                                      15.

<PAGE>

            (i)   CONSIDERATION. At the time of grant of a Stock Unit Award, the
Board will determine the consideration, if any, to be paid by the Participant
upon delivery of each share of Common Stock subject to the Stock Unit Award. To
the extent required by applicable law, the consideration to be paid by the
Participant for each share of Common Stock subject to a Stock Unit Award will
not be less than the par value of a share of Common Stock. The consideration may
be paid in any form permitted under applicable law.

            (ii)  VESTING. At the time of the grant of a Stock Unit Award, the
Board may impose such restrictions or conditions to the vesting of the Stock
Unit Award as it, in its sole discretion, deems appropriate.

            (iii) PAYMENT. A Stock Unit Award may be settled by the delivery of
shares of Common Stock, their cash equivalent, any combination thereof or in any
other form of consideration, as determined by the Board and contained in the
Stock Unit Award Agreement.

            (iv)  ADDITIONAL RESTRICTIONS. At the time of the grant of a Stock
Unit Award, the Board, as it deems appropriate, may impose such restrictions or
conditions that delay the delivery of the shares of Common Stock (or their cash
equivalent) subject to a Stock Unit Award after the vesting of such Stock Unit
Award.

            (v)   DIVIDEND EQUIVALENTS. Dividend equivalents may be credited in
respect of shares of Common Stock covered by a Stock Unit Award, as determined
by the Board and contained in the Stock Unit Award Agreement. At the sole
discretion of the Board, such dividend equivalents may be converted into
additional shares of Common Stock covered by the Stock Unit Award in such manner
as determined by the Board. Any additional shares covered by the Stock Unit
Award credited by reason of such dividend equivalents will be subject to all the
terms and conditions of the underlying Stock Unit Award Agreement to which they
relate.

            (vi)  TERMINATION OF PARTICIPANT'S CONTINUOUS SERVICE. Except as
otherwise provided in the applicable Stock Unit Award Agreement, such portion of
the Stock Unit Award that has not vested will be forfeited upon the
Participant's termination of Continuous Service.

            (vii) TRANSFERABILITY. Rights to purchase or receive shares of
Common Stock or other payment under a Stock Unit Award shall be transferable by
the Participant only upon such terms and conditions as are set forth in the
Stock Unit Award Agreement, as the Board shall determine in its sole discretion,
and so long as Common Stock awarded under the Stock Unit Award remains subject
to the terms of the Stock Unit Award Agreement.

      (d)   STOCK APPRECIATION RIGHTS. Each Stock Appreciation Right Agreement
shall be in such form and shall contain such terms and conditions as the Board
shall deem appropriate. The terms and conditions of Stock Appreciation Right
Agreements may change from time to time, and the terms and conditions of
separate Stock Appreciation Right Agreements need not be identical; provided,
however, that each Stock Appreciation Right Agreement shall include (through
incorporation of the provisions hereof by reference in the agreement or
otherwise) the substance of each of the following provisions:

            (i)   STRIKE PRICE AND CALCULATION OF APPRECIATION. Each Stock
Appreciation Right will be denominated in shares of Common Stock equivalents.
The appreciation

                                      16.

<PAGE>

distribution payable on the exercise of a Stock Appreciation Right will be not
greater than an amount equal to the excess of (A) the aggregate Fair Market
Value (on the date of the exercise of the Stock Appreciation Right) of a number
of shares of Common Stock equal to the number of share of Common Stock
equivalents in which the Participant is vested under such Stock Appreciation
Right, and with respect to which the Participant is exercising the Stock
Appreciation Right on such date, over (B) an amount (the strike price) that will
be determined by the Board at the time of grant of the Stock Appreciation Right.

            (ii)  VESTING. At the time of the grant of a Stock Appreciation
Right, the Board may impose such restrictions or conditions to the vesting of
such Stock Appreciation Right as it, in its sole discretion, deems appropriate.

            (iii) EXERCISE. To exercise any outstanding Stock Appreciation
Right, the Participant must provide written notice of exercise to the Company in
compliance with the provisions of the Stock Appreciation Right Agreement
evidencing such Stock Appreciation Right.

            (iv)  PAYMENT. The appreciation distribution in respect to a Stock
Appreciation Right may be paid in Common Stock, in cash, in any combination of
the two or in any other form of consideration, as determined by the Board and
contained in the Stock Appreciation Right Agreement evidencing such Stock
Appreciation Right.

            (v)   TERMINATION OF CONTINUOUS SERVICE. In the event that a
Participant's Continuous Service terminates, the Participant may exercise his or
her Stock Appreciation Right (to the extent that the Participant was entitled to
exercise such Stock Appreciation Right as of the date of termination) but only
within such period of time ending on the earlier of (i) the date three (3)
months following the termination of the Participant's Continuous Service (or
such longer or shorter period specified in the Stock Appreciation Right
Agreement) or (ii) the expiration of the term of the Stock Appreciation Right as
set forth in the Stock Appreciation Right Agreement. If, after termination, the
Participant does not exercise his or her Stock Appreciation Right within the
time specified herein or in the Stock Appreciation Right Agreement (as
applicable), the Stock Appreciation Right shall terminate.

      (e)   OTHER STOCK AWARDS. Other forms of Stock Awards valued in whole or
in part by reference to, or otherwise based on, Common Stock may be granted
either alone or in addition to Stock Awards provided for under Section 6 and the
preceding provisions of this Section 7. Subject to the provisions of the Plan,
the Board shall have sole and complete authority to determine the persons to
whom and the time or times at which such Other Stock Awards will be granted, the
number of shares of Common Stock (or the cash equivalent thereof) to be granted
pursuant to such Awards and all other terms and conditions of such Awards.

8.    COVENANTS OF THE COMPANY.

      (a)   AVAILABILITY OF SHARES. During the terms of the Stock Awards, the
Company shall keep available at all times the number of shares of Common Stock
required to satisfy such Stock Awards.

                                      17.

<PAGE>

      (b)   SECURITIES LAW COMPLIANCE. The Company shall seek to obtain from
each regulatory commission or agency having jurisdiction over the Plan such
authority as may be required to grant Stock Awards and to issue and sell shares
of Common Stock upon exercise of the Stock Awards; provided, however, that this
undertaking shall not require the Company to register under the Securities Act
the Plan, any Stock Award or any Common Stock issued or issuable pursuant to any
such Stock Award. If, after reasonable efforts, the Company is unable to obtain
from any such regulatory commission or agency the authority which counsel for
the Company deems necessary for the lawful issuance and sale of Common Stock
under the Plan, the Company shall be relieved from any liability for failure to
issue and sell Common Stock upon exercise of such Stock Awards unless and until
such authority is obtained.

9.    USE OF PROCEEDS FROM STOCK.

      Proceeds from the sale of Common Stock pursuant to Stock Awards shall
constitute general funds of the Company.

10.   MISCELLANEOUS.

      (a)   ACCELERATION OF EXERCISABILITY AND VESTING. The Board shall have the
power to accelerate the time at which a Stock Award may first be exercised or
the time during which a Stock Award or any part thereof will vest in accordance
with the Plan, notwithstanding the provisions in the Stock Award stating the
time at which it may first be exercised or the time during which it will vest.

      (b)   STOCKHOLDER RIGHTS. No Participant shall be deemed to be the holder
of, or to have any of the rights of a holder with respect to, any shares of
Common Stock subject to such Stock Award unless and until such Participant has
satisfied all requirements for exercise of the Stock Award pursuant to its
terms.

      (c)   NO EMPLOYMENT OR OTHER SERVICE RIGHTS. Nothing in the Plan, any
Stock Award Agreement or other instrument executed thereunder or any Stock Award
granted pursuant thereto shall confer upon any Participant any right to continue
to serve the Company or an Affiliate in the capacity in effect at the time the
Stock Award was granted or shall affect the right of the Company or an Affiliate
to terminate (i) the employment of an Employee with or without notice and with
or without cause, (ii) the service of a Consultant pursuant to the terms of such
Consultant's agreement with the Company or an Affiliate or (iii) the service of
a Director pursuant to the Bylaws of the Company or an Affiliate, and any
applicable provisions of the corporate law of the state in which the Company or
the Affiliate is incorporated, as the case may be.

      (d)   INCENTIVE STOCK OPTION $100,000 LIMITATION. To the extent that the
aggregate Fair Market Value (determined at the time of grant) of Common Stock
with respect to which Incentive Stock Options are exercisable for the first time
by any Optionholder during any calendar year (under all plans of the Company and
its Affiliates) exceeds one hundred thousand dollars ($100,000), the Options or
portions thereof that exceed such limit (according to the order in which they
were granted) shall be treated as Nonstatutory Stock Options, notwithstanding
any contrary provision of the applicable Option Agreement(s).

                                      18.

<PAGE>

      (e)   INVESTMENT ASSURANCES. The Company may require a Participant, as a
condition of exercising or acquiring Common Stock under any Stock Award, (i) to
give written assurances satisfactory to the Company as to the Participant's
knowledge and experience in financial and business matters and/or to employ a
purchaser representative reasonably satisfactory to the Company who is
knowledgeable and experienced in financial and business matters and that he or
she is capable of evaluating, alone or together with the purchaser
representative, the merits and risks of exercising the Stock Award; and (ii) to
give written assurances satisfactory to the Company stating that the Participant
is acquiring Common Stock subject to the Stock Award for the Participant's own
account and not with any present intention of selling or otherwise distributing
the Common Stock. The foregoing requirements, and any assurances given pursuant
to such requirements, shall be inoperative if (1) the issuance of the shares of
Common Stock upon the exercise or acquisition of Common Stock under the Stock
Award has been registered under a then currently effective registration
statement under the Securities Act or (2) as to any particular requirement, a
determination is made by counsel for the Company that such requirement need not
be met in the circumstances under the then applicable securities laws. The
Company may, upon advice of counsel to the Company, place legends on stock
certificates issued under the Plan as such counsel deems necessary or
appropriate in order to comply with applicable securities laws, including, but
not limited to, legends restricting the transfer of the Common Stock.

      (f)   WITHHOLDING OBLIGATIONS. To the extent provided by the terms of a
Stock Award Agreement, the Company, in its sole discretion, may satisfy any
federal, state or local tax withholding obligation relating to a Stock Award by
any of the following means (in addition to the Company's right to withhold from
any compensation paid to the Participant by the Company) or by a combination of
such means: (i) causing the Participant to tender a cash payment; (ii)
withholding shares of Common Stock from the shares of Common Stock issued or
otherwise issuable to the Participant in connection with the Stock Award; or
(iii) by such other method as may be set forth in the Stock Award Agreement.

      (g)   ELECTRONIC DELIVERY. Any reference herein to a "written" agreement
or document shall include any agreement or document delivered electronically or
posted on the Company's intranet.

11.   ADJUSTMENTS UPON CHANGES IN STOCK.

      (a)   CAPITALIZATION ADJUSTMENTS. If any change is made in, or other event
occurs with respect to, the Common Stock subject to the Plan or subject to any
Stock Award without the receipt of consideration by the Company (through merger,
consolidation, reorganization, recapitalization, reincorporation, stock
dividend, dividend in property other than cash, stock split, liquidating
dividend, combination of shares, exchange of shares, change in corporate
structure or other transaction not involving the receipt of consideration by the
Company (each a "Capitalization Adjustment"), the Plan will be appropriately
adjusted in the class(es) and maximum number of securities subject to the Plan
pursuant to Sections 4(a) and 4(b), and the outstanding Stock Awards will be
appropriately adjusted in the class(es) and number of securities and price per
share of Common Stock subject to such outstanding Stock Awards. The Board shall
make such adjustments, and its determination shall be final, binding and
conclusive.

                                      19.

<PAGE>

(Notwithstanding the foregoing, the conversion of any convertible securities of
the Company shall not be treated as a transaction "without receipt of
consideration" by the Company.)

      (b)   DISSOLUTION OR LIQUIDATION. In the event of a dissolution or
liquidation of the Company, then all outstanding Stock Awards shall terminate
immediately prior to the completion of such dissolution or liquidation.

      (c)   CORPORATE TRANSACTION. In the event of a Corporate Transaction, any
surviving corporation or acquiring corporation (or the surviving or acquiring
corporation's parent company) may assume or continue any or all Stock Awards
outstanding under the Plan or may substitute similar stock awards for Stock
Awards outstanding under the Plan (it being understood that similar stock awards
include, but are not limited to, awards to acquire the same consideration paid
to the stockholders of the Company, as the case may be, pursuant to the
Corporate Transaction), and any reacquisition or repurchase rights held by the
Company in respect of Common Stock issued pursuant to Stock Awards may be
assigned by the Company to the successor of the Company (or the successor's
parent company), if any, in connection with such Corporate Transaction. In the
event that any surviving corporation or acquiring corporation (or its parent
company) does not assume or continue all such outstanding Stock Awards or
substitute similar stock awards for all such outstanding Stock Awards, then with
respect to Stock Awards that have been not assumed, continued or substituted and
are held by Participants whose Continuous Service has not terminated prior to
the effective time of the Corporate Transaction, the vesting of such Stock
Awards (and, if applicable, the time at which such Stock Awards may be
exercised) shall (contingent upon the effectiveness of the Corporate
Transaction) be accelerated in full to a date prior to the effective time of
such Corporate Transaction as the Board shall determine (or, if the Board shall
not determine such a date, to the date that is five (5) days prior to the
effective time of the Corporate Transaction), and such Stock Awards shall
terminate if not exercised (if applicable) at or prior to such effective time,
and any reacquisition or repurchase rights held by the Company with respect to
such Stock Awards shall (contingent upon the effectiveness of the Corporate
Transaction) lapse. With respect to any other Stock Awards outstanding under the
Plan that have not been assumed, continued or substituted, the vesting of such
Stock Awards (and, if applicable, the time at which such Stock Award may be
exercised) shall not be accelerated, unless otherwise provided in a written
agreement between the Company or any Affiliate and the holder of such Stock
Award, and such Stock Awards shall terminate if not exercised (if applicable)
prior to the effective time of the Corporate Transaction.

      (d)   CHANGE IN CONTROL. A Stock Award may be subject to additional
acceleration of vesting and exercisability upon or after a Change in Control as
may be provided in the Stock Award Agreement for such Stock Award or as may be
provided in any other written agreement between the Company or any Affiliate and
the Participant, but in the absence of such provision, no such acceleration
shall occur.

12.   AMENDMENT OF THE PLAN AND STOCK AWARDS.

      (a)   AMENDMENT OF PLAN. Subject to the limitations, if any, of applicable
law, the Board at any time, and from time to time, may amend the Plan. However,
except as provided in Section 11(a) relating to Capitalization Adjustments, no
amendment shall be effective unless

                                      20.

<PAGE>

approved by the stockholders of the Company to the extent stockholder approval
is necessary to satisfy applicable law.

      (b)   STOCKHOLDER APPROVAL. The Board, in its sole discretion, may submit
any other amendment to the Plan for stockholder approval, including, but not
limited to, amendments to the Plan intended to satisfy the requirements of
Section 162(m) of the Code and the regulations thereunder regarding the
exclusion of performance-based compensation from the limit on corporate
deductibility of compensation paid to Covered Employees.

      (c)   CONTEMPLATED AMENDMENTS. It is expressly contemplated that the Board
may amend the Plan in any respect the Board deems necessary or advisable to
provide eligible Employees with the maximum benefits provided or to be provided
under the provisions of the Code and the regulations promulgated thereunder
relating to Incentive Stock Options and/or to bring the Plan and/or Incentive
Stock Options granted under it into compliance therewith.

      (d)   NO IMPAIRMENT OF RIGHTS. Rights under any Stock Award granted before
amendment of the Plan shall not be impaired by any amendment of the Plan unless
(i) the Company requests the consent of the Participant and (ii) the Participant
consents in writing.

      (e)   AMENDMENT OF STOCK AWARDS. The Board at any time, and from time to
time, may amend the terms of any one or more Stock Awards, including, but not
limited to, amendments to provide terms more favorable than previously provided
in the agreement evidencing a Stock Award, subject to any specified limits in
the Plan that are not subject to Board discretion; provided, however, that the
rights under any Stock Award shall not be impaired by any such amendment unless
(i) the Company requests the consent of the Participant and (ii) the Participant
consents in writing.

13.   TERMINATION OR SUSPENSION OF THE PLAN.

      (a)   PLAN TERM. The Board may suspend or terminate the Plan at any time.
Unless sooner terminated, the Plan shall terminate on the day before the tenth
(10th) anniversary of the date the Plan is adopted by the Board or approved by
the stockholders of the Company, whichever is earlier. No Stock Awards may be
granted under the Plan while the Plan is suspended or after it is terminated.

      (b)   NO IMPAIRMENT OF RIGHTS. Suspension or termination of the Plan shall
not impair rights and obligations under any Stock Award granted while the Plan
is in effect except with the written consent of the Participant.

14.   EFFECTIVE DATE OF PLAN.

      This Plan (as an amendment and restatement of the Prior Plan) shall become
effective on the IPO Date, but no Stock Award shall be exercised (or, in the
case of a stock bonus, shall be granted) unless and until the Plan has been
approved by the stockholders of the Company, which approval shall be within
twelve (12) months before or after the date the Plan is adopted by the Board.

                                      21.

<PAGE>

15.   CHOICE OF LAW.

      The law of the State of Delaware shall govern all questions concerning the
construction, validity and interpretation of this Plan, without regard to such
state's conflict of laws rules.

                                      22.

<PAGE>

                       VOLTERRA SEMICONDUCTOR CORPORATION
                           2004 EQUITY INCENTIVE PLAN

                            STOCK OPTION GRANT NOTICE

Volterra Semiconductor Corporation (the "Company"), pursuant to its 2004 Equity
Incentive Plan (the "Plan"), hereby grants to Optionholder an option to purchase
the number of shares of the Company's Common Stock set forth below. This option
is subject to all of the terms and conditions as set forth herein and in the
Stock Option Agreement, the Plan and the Notice of Exercise, all of which are
attached hereto and incorporated herein in their entirety.

        Optionholder:                         _________________________________
        Date of Grant:                        _________________________________
        Vesting Commencement Date:            _________________________________
        Number of Shares Subject to Option:   _________________________________
        Exercise Price (Per Share):           _________________________________
        Total Exercise Price:                 _________________________________
        Expiration Date:                      _________________________________

TYPE OF GRANT:     [ ] Incentive Stock Option(1)  [  ]Nonstatutory Stock Option

EXERCISE SCHEDULE: [X] Same as Vesting Schedule   [ ] Early  Exercise  Permitted

VESTING SCHEDULE:

PAYMENT:           By one or a combination of the following items (described in
                   the Stock Option Agreement):

                   [ ] By cash or check
                   [ ] Pursuant to a Regulation T Program if the Shares are
                       publicly traded
                   [ ] By delivery of already-owned shares if the Shares are
                       publicly traded
                   [ ] By net exercise
                   [ ] By deferred payment

ADDITIONAL TERMS/ACKNOWLEDGEMENTS: The undersigned Optionholder acknowledges
receipt of, and understands and agrees to, this Stock Option Grant Notice, the
Stock Option Agreement and the Plan. Optionholder further acknowledges that as
of the Date of Grant, this Stock Option Grant Notice, the Stock Option Agreement
and the Plan set forth the entire understanding between Optionholder and the
Company regarding the acquisition of stock in the Company and supersede all
prior oral and written agreements on that subject with the exception of (i)
options previously granted and delivered to Optionholder under the Plan, and
(ii) the following agreements only:

         OTHER AGREEMENTS:
                                ________________________________________________
                                ________________________________________________

____________________
(1) If this is an Incentive Stock Option, it (plus other outstanding Incentive
Stock Options) cannot be first exercisable for more than $100,000 in value
(measured by exercise price) in any calendar year. Any excess over $100,000 is a
Nonstatutory Stock Option.

<PAGE>

VOLTERRA SEMICONDUCTOR CORPORATION              OPTIONHOLDER:

By: ______________________________              ________________________________
               Signature                                   Signature

Title: ___________________________              Date: __________________________

Date:_____________________________

ATTACHMENTS: Stock Option Agreement, 2004 Equity Incentive Plan and Notice of
Exercise

<PAGE>

                                  ATTACHMENT I

                             STOCK OPTION AGREEMENT

<PAGE>

                                  ATTACHMENT II

                           2004 EQUITY INCENTIVE PLAN

<PAGE>

                                 ATTACHMENT III

                               NOTICE OF EXERCISE

<PAGE>

                       VOLTERRA SEMICONDUCTOR CORPORATION
                           2004 EQUITY INCENTIVE PLAN

                             STOCK OPTION AGREEMENT
              (INCENTIVE STOCK OPTION OR NONSTATUTORY STOCK OPTION)

      Pursuant to your Stock Option Grant Notice ("Grant Notice") and this Stock
Option Agreement, Volterra Semiconductor Corporation (the "Company") has granted
you an option under its 2004 Equity Incentive Plan (the "Plan") to purchase the
number of shares of the Company's Common Stock indicated in your Grant Notice at
the exercise price indicated in your Grant Notice. Defined terms not explicitly
defined in this Stock Option Agreement but defined in the Plan shall have the
same definitions as in the Plan.

      The details of your option are as follows:

      1.    VESTING. Subject to the limitations contained herein, your option
will vest as provided in your Grant Notice, provided that vesting will cease
upon the termination of your Continuous Service.

      2.    NUMBER OF SHARES AND EXERCISE PRICE. The number of shares of Common
Stock subject to your option and your exercise price per share referenced in
your Grant Notice may be adjusted from time to time for Capitalization
Adjustments.

      3.    EXERCISE PRIOR TO VESTING ("EARLY EXERCISE"). If permitted in your
Grant Notice (i.e., the "Exercise Schedule" indicates that "Early Exercise" of
your option is permitted) and subject to the provisions of your option, you may
elect at any time that is both (i) during the period of your Continuous Service
and (ii) during the term of your option, to exercise all or part of your option,
including the nonvested portion of your option; provided, however, that:

            (a)   a partial exercise of your option shall be deemed to cover
first vested shares of Common Stock and then the earliest vesting installment of
unvested shares of Common Stock;

            (b)   any shares of Common Stock so purchased from installments that
have not vested as of the date of exercise shall be subject to the purchase
option in favor of the Company as described in the Company's form of Early
Exercise Stock Purchase Agreement;

            (c)   you shall enter into the Company's form of Early Exercise
Stock Purchase Agreement with a vesting schedule that will result in the same
vesting as if no early exercise had occurred; and

            (d)   if your option is an Incentive Stock Option, then, to the
extent that the aggregate Fair Market Value (determined at the time of grant) of
the shares of Common Stock with respect to which your option plus all other
Incentive Stock Options you hold are exercisable for the first time by you
during any calendar year (under all plans of the Company and its

                                       1.

<PAGE>

Affiliates) exceeds one hundred thousand dollars ($100,000), your option(s) or
portions thereof that exceed such limit (according to the order in which they
were granted) shall be treated as Nonstatutory Stock Options.

      4.    METHOD OF PAYMENT. Payment of the exercise price is due in full upon
exercise of all or any part of your option. You may elect to make payment of the
exercise price in cash or by check or in any other manner PERMITTED BY YOUR
GRANT NOTICE, which may include one or more of the following:

            (a)   In the Company's sole discretion at the time your option is
exercised and provided that at the time of exercise the Common Stock is publicly
traded and quoted regularly in The Wall Street Journal, pursuant to a program
developed under Regulation T as promulgated by the Federal Reserve Board that,
prior to the issuance of Common Stock, results in either the receipt of cash (or
check) by the Company or the receipt of irrevocable instructions to pay the
aggregate exercise price to the Company from the sales proceeds.

            (b)   Provided that at the time of exercise the Common Stock is
publicly traded and quoted regularly in The Wall Street Journal, by delivery of
already-owned shares of Common Stock either that you have held for the period
required to avoid a charge to the Company's reported earnings (generally six (6)
months) or that you did not acquire, directly or indirectly from the Company,
that are owned free and clear of any liens, claims, encumbrances or security
interests, and that are valued at Fair Market Value on the date of exercise.
"Delivery" for these purposes, in the sole discretion of the Company at the time
you exercise your option, shall include delivery to the Company of your
attestation of ownership of such shares of Common Stock in a form approved by
the Company. Notwithstanding the foregoing, you may not exercise your option by
tender to the Company of Common Stock to the extent such tender would violate
the provisions of any law, regulation or agreement restricting the redemption of
the Company's stock.

            (c)   Pursuant to the following deferred payment alternative:

                  (i)   Not less than one hundred percent (100%) of the
aggregate exercise price, plus accrued interest, shall be due four (4) years
from date of exercise or, at the Company's election, upon termination of your
Continuous Service.

                                       2.

<PAGE>

                  (ii)  Interest shall be compounded at least annually and shall
be charged at the minimum rate of interest necessary to avoid (1) the treatment
as interest, under any applicable provisions of the Code, of any amounts other
than amounts stated to be interest under the deferred payment arrangement and
(2) the treatment of the Option as a variable award for financial accounting
purposes.

                  (iii) At any time that the Company is incorporated in
Delaware, payment of the Common Stock's "par value," as defined in the Delaware
General Corporation Law, shall be made in cash and not by deferred payment.

                  (iv)  In order to elect the deferred payment alternative, you
must, as a part of your written notice of exercise, give notice of the election
of this payment alternative and, in order to secure the payment of the deferred
exercise price to the Company hereunder, if the Company so requests, you must
tender to the Company a promissory note and a pledge agreement covering the
purchased shares of Common Stock, both in form and substance satisfactory to the
Company, or such other or additional documentation as the Company may request.

      5.    WHOLE SHARES. You may exercise your option only for whole shares of
Common Stock.

      6.    SECURITIES LAW COMPLIANCE. Notwithstanding anything to the contrary
contained herein, you may not exercise your option unless the shares of Common
Stock issuable upon such exercise are then registered under the Securities Act
or, if such shares of Common Stock are not then so registered, the Company has
determined that such exercise and issuance would be exempt from the registration
requirements of the Securities Act. The exercise of your option also must comply
with other applicable laws and regulations governing your option, and you may
not exercise your option if the Company determines that such exercise would not
be in material compliance with such laws and regulations.

      7.    TERM. You may not exercise your option before the commencement or
after the expiration of its term. The term of your option commences on the Date
of Grant and expires upon the earliest of the following:

            (a)   three (3) months after the termination of your Continuous
Service for any reason other than your Disability or death or upon a Change in
Control, provided that if during any part of such three (3) month period your
option is not exercisable solely because of the condition set forth in Section
6, your option shall not expire until the earlier of the Expiration Date or
until it shall have been exercisable for an aggregate period of three (3) months
after the termination of your Continuous Service;

            (b)   twelve (12) months after the termination of your Continuous
Service due to your Disability;

            (c)   eighteen (18) months after your death if you die either during
your Continuous Service or within three (3) months after your Continuous Service
terminates;

                                       3.

<PAGE>

            (d)   twelve (12) months after the termination of your Continuous
Service if such termination occurs as of, or within thirteen (13) months
[FOLLOWING] [OF], the effective time of such Change in Control;

            (e)   the Expiration Date indicated in your Grant Notice; or

            (f)   the day before the tenth (10th) anniversary of the Date of
Grant.

      If your option is an Incentive Stock Option, note that to obtain the
federal income tax advantages associated with an Incentive Stock Option, the
Code requires that at all times beginning on the date of grant of your option
and ending on the day three (3) months before the date of your option's
exercise, you must be an employee of the Company or an Affiliate, except in the
event of your death or your permanent and total disability, as defined in
Section 22(e) of the Code. (The definition of disability in Section 22(e) of the
Code is different from the definition of the Disability under the Plan). The
Company has provided for extended exercisability of your option under certain
circumstances for your benefit but cannot guarantee that your option will
necessarily be treated as an Incentive Stock Option if you continue to provide
services to the Company or an Affiliate as a Consultant or Director after your
employment terminates or if you otherwise exercise your option more than three
(3) months after the date your employment with the Company or an Affiliate
terminates.

      8.    EXERCISE.

            (a)   You may exercise the vested portion of your option (and the
unvested portion of your option if your Grant Notice so permits) during its term
by delivering a Notice of Exercise (in a form designated by the Company)
together with the exercise price to the Secretary of the Company, or to such
other person as the Company may designate, during regular business hours,
together with such additional documents as the Company may then require.

            (b)   By exercising your option you agree that, as a condition to
any exercise of your option, the Company may require you to enter into an
arrangement providing for the payment by you to the Company of any tax
withholding obligation of the Company arising by reason of (1) the exercise of
your option, (2) the lapse of any substantial risk of forfeiture to which the
shares of Common Stock are subject at the time of exercise, or (3) the
disposition of shares of Common Stock acquired upon such exercise.

            (c)   If your option is an Incentive Stock Option, by exercising
your option you agree that you will notify the Company in writing within fifteen
(15) days after the date of any disposition of any of the shares of the Common
Stock issued upon exercise of your option that occurs within two (2) years after
the date of your option grant or within one (1) year after such shares of Common
Stock are transferred upon exercise of your option.

      9.    TRANSFERABILITY. Your option is not transferable, except by will or
by the laws of descent and distribution, and is exercisable during your life
only by you. Notwithstanding the foregoing, by delivering written notice to the
Company, in a form satisfactory to the Company,

                                       4.

<PAGE>

you may designate a third party who, in the event of your death, shall
thereafter be entitled to exercise your option.

      10.   OPTION NOT A SERVICE CONTRACT. Your option is not an employment or
service contract, and nothing in your option shall be deemed to create in any
way whatsoever any obligation on your part to continue in the employ of the
Company or an Affiliate, or of the Company or an Affiliate to continue your
employment. In addition, nothing in your option shall obligate the Company or an
Affiliate, their respective stockholders, Boards of Directors, Officers or
Employees to continue any relationship that you might have as a Director or
Consultant for the Company or an Affiliate.

      11.   WITHHOLDING OBLIGATIONS.

            (a)   At the time you exercise your option, in whole or in part, or
at any time thereafter as requested by the Company, you hereby authorize
withholding from payroll and any other amounts payable to you, and otherwise
agree to make adequate provision for (including by means of a "cashless
exercise" pursuant to a program developed under Regulation T as promulgated by
the Federal Reserve Board to the extent permitted by the Company), any sums
required to satisfy the federal, state, local and foreign tax withholding
obligations of the Company or an Affiliate, if any, which arise in connection
with the exercise of your option.

            (b)   Upon your request and subject to approval by the Company, in
its sole discretion, and compliance with any applicable legal conditions or
restrictions, the Company may withhold from fully vested shares of Common Stock
otherwise issuable to you upon the exercise of your option a number of whole
shares of Common Stock having a Fair Market Value, determined by the Company as
of the date of exercise, not in excess of the minimum amount of tax required to
be withheld by law (or such lower amount as may be necessary to avoid variable
award accounting). If the date of determination of any tax withholding
obligation is deferred to a date later than the date of exercise of your option,
share withholding pursuant to the preceding sentence shall not be permitted
unless you make a proper and timely election under Section 83(b) of the Code,
covering the aggregate number of shares of Common Stock acquired upon such
exercise with respect to which such determination is otherwise deferred, to
accelerate the determination of such tax withholding obligation to the date of
exercise of your option. Notwithstanding the filing of such election, shares of
Common Stock shall be withheld solely from fully vested shares of Common Stock
determined as of the date of exercise of your option that are otherwise issuable
to you upon such exercise. Any adverse consequences to you arising in connection
with such share withholding procedure shall be your sole responsibility.

            (c)   You may not exercise your option unless the tax withholding
obligations of the Company and/or any Affiliate are satisfied. Accordingly, you
may not be able to exercise your option when desired even though your option is
vested, and the Company shall have no obligation to issue a certificate for such
shares of Common Stock or release such shares of Common Stock from any escrow
provided for herein unless such obligations are satisfied.

      12.   NOTICES. Any notices provided for in your option or the Plan shall
be given in writing and shall be deemed effectively given upon receipt or, in
the case of notices delivered by

                                       5.

<PAGE>

mail by the Company to you, five (5) days after deposit in the United States
mail, postage prepaid, addressed to you at the last address you provided to the
Company.

      13.   GOVERNING PLAN DOCUMENT. Your option is subject to all the
provisions of the Plan, the provisions of which are hereby made a part of your
option, and is further subject to all interpretations, amendments, rules and
regulations, which may from time to time be promulgated and adopted pursuant to
the Plan. In the event of any conflict between the provisions of your option and
those of the Plan, the provisions of the Plan shall control.

                                       6.

<PAGE>

                               NOTICE OF EXERCISE

Volterra Semiconductor Corporation
3839 Spinnaker Court
Fremont, CA 94538-6537                         Date of Exercise: _______________

Ladies and Gentlemen:

      This constitutes notice under my stock option that I elect to purchase the
number of shares for the price set forth below.

    Type of option (check one):                 [ ] Incentive   [ ] Nonstatutory

    Stock option dated:                         _______________

    Number of shares as
    to which option is
    exercised:                                  _______________

    Certificates to be
    issued in name of:                          _______________

    Total exercise price:                       $______________

    Cash payment delivered
    herewith:                                   $______________

    Value of ________ shares of
    Volterra Semiconductor Corporation
    Common Stock delivered herewith(1):         $______________

    [Promissory note delivered                  $______________]
    herewith:

      By this exercise, I agree (i) to provide such additional documents as you
may require pursuant to the terms of the Volterra Semiconductor Corporation 2004
Equity Incentive Plan, (ii) to provide for the payment by me to you (in the
manner designated by you) of your withholding

-------------------
(1) Shares must meet the public trading requirements set forth in the option.
Shares must be valued in accordance with the terms of the option being
exercised, must have been owned for the minimum period required in the option,
and must be owned free and clear of any liens, claims, encumbrances or security
interests. Certificates must be endorsed or accompanied by an executed
assignment separate from certificate.

                                       1.

<PAGE>

obligation, if any, relating to the exercise of this option, and (iii) if this
exercise relates to an incentive stock option, to notify you in writing within
fifteen days after the date of any disposition of any of the shares of Common
Stock issued upon exercise of this option that occurs within two (2) years after
the date of grant of this option or within one (1) year after such shares of
Common Stock are issued upon exercise of this option.

                                                   Very truly yours,

                                                   _____________________________

                                       2.

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