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                                                                    EXHIBIT 10.4

                       VOLTERRA SEMICONDUCTOR CORPORATION

                           2004 EQUITY INCENTIVE PLAN

                              ADOPTED: MAY 7, 2004
                    APPROVED BY STOCKHOLDERS: JUNE 18, 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.

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            (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.

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      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.

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            (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.

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      (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.

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      (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.

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      (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.

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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.

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            (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 eight million four hundred
eighty-three thousand seven hundred fifty (8,483,750) 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.

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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 eight million four hundred
eighty-three thousand seven hundred fifty (8,483,750) 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.

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      (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.<PAGE>

                                                                    EXHIBIT 10.5

                       VOLTERRA SEMICONDUCTOR CORPORATION

                 2004 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN

                             ADOPTED: MAY 17, 2004
                    APPROVED BY STOCKHOLDERS: June 18, 2004

1.    PURPOSES.

      (a)   ELIGIBLE OPTION RECIPIENTS. The persons eligible to receive Options
are the Non-Employee Directors of the Company.

      (b)   AVAILABLE OPTIONS. The purpose of the Plan is to provide a means by
which Non-Employee Directors may be given an opportunity to benefit from
increases in value of the Common Stock through the granting of Nonstatutory
Stock Options.

      (c)   GENERAL PURPOSE. The Company, by means of the Plan, seeks to retain
the services of its Non-Employee Directors, to secure and retain the services of
new Non-Employee Directors and to provide incentives for such persons to exert
maximum efforts for the success of the Company and its Affiliates.

2.    DEFINITIONS.

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

      (a)   "ACCOUNTANT" means the independent public accountants of the
Company.

      (b)   "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.

      (c)   "ANNUAL GRANT" means an Option granted annually to all Non-Employee
Directors who meet the specified criteria pursuant to Section 6(b).

      (d)   "ANNUAL MEETING" means the annual meeting of the stockholders of the
Company.

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

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

      (g)   "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 Optionholder shall
supersede the foregoing definition with respect to Options 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).

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

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

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

      (k)   "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.

      (l)   "CONTINUOUS SERVICE" means that the Optionholder'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 Optionholder
renders service to the Company or an Affiliate as an Employee, Consultant or
Director or a change in the entity for which the Optionholder renders such
service, provided that there is no interruption or termination of the
Optionholder's service with the Company or an Affiliate, shall not terminate an
Optionholder's Continuous Service. For example, a change in status from a
Non-Employee Director of the Company to a Consultant of an Affiliate or an
Employee of the Company will 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 an Option only to such extent as may be
provided in the Company's leave of absence policy or in the written terms of the
Optionholder's leave of absence.

      (m)   "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.

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

      (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.

      (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.

                                       4.

<PAGE>

      (u)   "INITIAL GRANT" means an Option granted to a Non-Employee Director
who meets the specified criteria pursuant to Section 6(a).

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

      (w)   "NON-EMPLOYEE DIRECTOR" means a Director who is not an Employee.

      (x)   "NONSTATUTORY STOCK OPTION" means an Option not intended to qualify
as an incentive stock option within the meaning of Section 422 of the Code and
the regulations promulgated thereunder.

      (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 a Nonstatutory Stock Option 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 individual 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)  "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.

      (dd)  "PLAN" means this Volterra Semiconductor Corporation 2004
Non-Employee Directors' Stock Option Plan.

      (ee)  "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.

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

      (gg)  "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%).

                                       5.

<PAGE>

3.    ADMINISTRATION.

      (a)   ADMINISTRATION BY BOARD. The Board shall administer the Plan. The
Board may not delegate administration of the Plan to a committee.

      (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 the provisions of each Option to the extent not
specified in the Plan.

            (ii)  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.

            (iii) To amend the Plan or an Option as provided in Section 12.

            (iv)  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.

      (c)   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 relating to
adjustments upon changes in the Common Stock, the Common Stock that may be
issued pursuant to Options shall not exceed in the aggregate one hundred
twenty-five thousand (125,000) shares of Common Stock, plus an annual increase
for ten years beginning on December 31, 2004 and ending on (and including)
December 31, 2013 equal to the number of shares subject to Options granted
during the calendar year ending on such date. 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 described in the
prior sentence.

      (b)   REVERSION OF SHARES TO THE SHARE RESERVE. If any Option shall for
any reason expire or otherwise terminate, in whole or in part, without having
been exercised in full, the shares of Common Stock not acquired under such
Option shall revert to and again become available for issuance under the Plan.

      (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.

                                       6.

<PAGE>

5.    ELIGIBILITY.

      The Options, as set forth in Section 6, automatically shall be granted
under the Plan to all Non-Employee Directors who meet the criteria specified in
Section 6.

6.    NON-DISCRETIONARY GRANTS.

      (a)   INITIAL GRANTS. Without any further action of the Board, each person
who after the IPO Date is elected or appointed for the first time to be a
Non-Employee Director automatically shall, upon the date of his or her initial
election or appointment to be a Non-Employee Director, be granted an Initial
Grant to purchase twenty-five thousand (25,000) shares of Common Stock on the
terms and conditions set forth herein.

      (b)   ANNUAL GRANTS. Without any further action of the Board, on the date
of each Annual Meeting, commencing with the Annual Meeting in 2005, each person
who is then a Non-Employee Director automatically shall be granted an Annual
Grant to purchase six thousand two hundred fifty (6,250) shares of Common Stock
on the terms and conditions set forth herein; provided, however, that if the
person has not been serving as a Non-Employee Director for the entire period
since the preceding Annual Meeting, then the number of shares subject to such
Annual Grant shall be reduced pro rata for each full quarter prior to the date
of grant during which such person did not serve as a Non- Employee Director.

7.    OPTION PROVISIONS.

      Each Option shall be in such form and shall contain such terms and
conditions as required by the Plan. Each Option shall contain such additional
terms and conditions, not inconsistent with the Plan, as the Board shall deem
appropriate. 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)   EXERCISE PRICE. The exercise price of each Option shall be one
hundred percent (100%) of the Fair Market Value of the stock subject to the
Option on the date the Option is granted.

      (c)   CONSIDERATION. The purchase price of stock acquired pursuant to an
Option may be paid, to the extent permitted by applicable law, in any
combination of (i) cash or check, (ii) delivery to the Company of other Common
Stock or (iii) 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. 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).

                                       7.

<PAGE>

      (d)   TRANSFERABILITY. Except as otherwise provided for in this Section,
an Option is transferable only by will or by the laws of descent and
distribution and exercisable only by the Optionholder during the life of the
Optionholder. However, an Option may be transferred for no consideration upon
written consent of the Board if (i) at the time of transfer, a Form S-8
registration statement under the Securities Act is available for the issuance of
shares by the Company upon the exercise of such transferred Option or (ii) the
transfer is to the Optionholder's employer at the time of transfer or an
affiliate of the Optionholder's employer at the time of transfer. Any such
transfer is subject to such limits as the Board may establish, and subject to
the transferee agreeing to remain subject to all the terms and conditions
applicable to the Option prior to such transfer. The forgoing right to transfer
the Option shall apply to the right to consent to amendments to the Stock Option
Agreement for such Option. In addition, until the Optionholder transfers the
Option, an 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.

      (e)   VESTING. Options shall vest as follows:

            (i)   Initial Grants: 1/4th of the shares shall vest one year after
the date of grant and 1/16th of the shares shall vest quarterly thereafter over
three (3) years.

            (ii)  Annual Grants: 1/4th of the shares shall vest one year after
the date of grant and 1/16th of the shares shall vest quarterly thereafter over
three (3) years.

      (f)   EARLY EXERCISE. The Option may, but need not, 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 shared 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 will not 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 accounting purposes) have
elapsed following exercise of the Option unless the Board otherwise specifically
provides in the Option.

      (g)   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.

(h) EXTENSION OF TERMINATION DATE. If the exercise of the Option following the
termination of the Optionholder's Continuous Service (other than upon the
Optionholder's death

                                       8.

<PAGE>

or Disability) would be prohibited at any time solely because the issuance of
shares would violate the registration requirements under the Securities Act,
then the Option shall terminate on the earlier of (i) the expiration of the term
of the Option as 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.

      (i)   DISABILITY OF OPTIONHOLDER. In the event 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 it as of the 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 (ii) the expiration of the term of the Option as
set forth in the Option Agreement. If, after termination, the Optionholder does
not exercise his or her Option within the time specified herein, the Option
shall terminate.

      (j)   DEATH OF OPTIONHOLDER. In the event (i) an Optionholder's Continuous
Service terminates as a result of the Optionholder's death or (ii) the
Optionholder dies within the three-month period after the termination of the
Optionholder's Continuous Service for a reason other than death, then the Option
may be exercised (to the extent the Optionholder was entitled to exercise the
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, but only
within the period ending on the earlier of (1) the date eighteen (18) months
following the date of death or (2) the expiration of the term of such Option as
set forth in the Option Agreement. If, after death, the Option is not exercised
within the time specified herein, the Option shall terminate.

      (k)   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.

8.    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
Options and to issue and sell shares of Common Stock upon exercise of the
Options; provided, however, that this undertaking shall not require the Company
to register under the Securities Act 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

                                       9.

<PAGE>

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

9.    USE OF PROCEEDS FROM STOCK.

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

10.   MISCELLANEOUS.

      (a)   STOCKHOLDER RIGHTS. No Optionholder 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 Optionholder has satisfied all requirements
for exercise of the Option pursuant to its terms.

      (b)   NO SERVICE RIGHTS. Nothing in the Plan or any instrument executed or
Option granted pursuant thereto shall confer upon any Optionholder any right to
continue to serve the Company as a Non-Employee Director 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.

      (c)   INVESTMENT ASSURANCES. The Company may require an Optionholder, as a
condition of exercising or acquiring stock under any Option, (i) to give written
assurances satisfactory to the Company as to the Optionholder'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 (ii) to give written assurances satisfactory
to the Company stating that the Optionholder is acquiring the stock subject to
the Option for the Optionholder'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 (1)
the issuance of the shares upon the exercise or acquisition of stock under the
Option 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 stock.

      (d)   WITHHOLDING OBLIGATIONS. The Optionholder may satisfy any federal,
state or local tax withholding obligation relating to the exercise or
acquisition of stock under an Option by any of the following means (in addition
to the Company's right to withhold from any compensation paid to the
Optionholder by the Company) or by a combination of such means: (i)

                                      10.

<PAGE>

tendering a cash payment; (ii) authorizing the Company to withhold shares from
the shares of the Common Stock otherwise issuable to the Optionholder as a
result of the exercise or acquisition of stock under the Option; provided,
however, that no shares of Common Stock are withheld with a value exceeding the
minimum amount of tax required to be withheld by law; or (iii) delivering to the
Company owned and unencumbered shares of the Common Stock.

      (e)   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 COMMON STOCK.

      (a)   CAPITALIZATION ADJUSTMENTS. If any change is made in, or other
events occur with respect to, the stock subject to the Plan, or subject to any
Option, 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 both to the
Plan pursuant to Section 4 and to the nondiscretionary Options specified in
Section 6, and the outstanding Options will be appropriately adjusted in the
class(es) and number of securities and price per share of stock subject to such
outstanding Options. The Board shall make such adjustments, and its
determination shall be final, binding and conclusive. (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 Options 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 Options
outstanding under the Plan or may substitute similar stock options for Options
outstanding under the Plan (it being understood that similar stock options
include, but are not limited to, options to acquire the same consideration paid
to the stockholders or the Company, as the case may be, pursuant to the
Corporate Transaction). In the event that any surviving corporation or acquiring
corporation (or its parent company) does not assume or continue all such
outstanding Options or substitute similar stock options for such outstanding
Options, then with respect to Options that have been not assumed, continued or
substituted and are held by Optionholders whose Continuous Service has not
terminated prior to the effective time of the Corporate Transaction, the vesting
of such Options (and, if applicable, the time at which such Options 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 the Options shall terminate if
not exercised (if applicable) at or prior to such effective time. With respect
to any other Options outstanding under the Plan that have not been

                                      11.

<PAGE>

assumed, continued or substituted, the vesting of such Options (and, if
applicable, the time at which such Options may be exercised) shall not be
accelerated unless otherwise provided in Section 11(d) or in a written agreement
between the Company or any Affiliate and the holder of such Options, and such
Options shall terminate if not exercised (if applicable) prior to the effective
time of the Corporate Transaction.

      (d)   CHANGE IN CONTROL. If a Change in Control occurs and an
Optionholder's Continuous Service with the Company has not terminated
immediately prior to the effective time of the Change in Control, then,
immediately prior to the effective time of such Change in Control (and
contingent upon the effectiveness of the Change in Control), the vesting and
exercisability of an Optionholder's Options shall be accelerated in full. In the
event that an Optionholder is required to resign his or her position as a
Non-Employee Director as a condition of a Change in Control, the outstanding
Options of such Optionholder shall become fully vested and exercisable
immediately prior to the effectiveness of such resignation (and contingent upon
the effectiveness of the Change in Control).

      (e)   PARACHUTE PAYMENTS. If the acceleration of the vesting and
exercisability of Options provided for in Section 11(c), together with payments
and other benefits of an Optionholder, (collectively, the "Payment") (i)
constitute a "parachute payment" within the meaning of Section 280G of the Code,
or any comparable successor provisions, and (ii) but for this Section 11(e)
would be subject to the excise tax imposed by Section 4999 of the Code, or any
comparable successor provisions (the "Excise Tax"), then such Payment shall be
either (1) provided to such Optionholder in full, or (2) provided to such
Optionholder as to such lesser extent that would result in no portion of such
Payment being subject to the Excise Tax, whichever of the foregoing amounts,
when taking into account applicable federal, state, local and foreign income and
employment taxes, the Excise Tax, and any other applicable taxes, results in the
receipt by such Optionholder, on an after-tax basis, of the greatest amount of
the Payment, notwithstanding that all or some portion of the Payment may be
subject to the Excise Tax.

            Unless the Company and such Optionholder otherwise agree in writing,
any determination required under this Section 11(e) shall be made in writing in
good faith by the Accountant. If a reduction in the Payment is to be made as
provided above, reductions shall occur in the following order unless the
Optionholder elects in writing a different order (provided, however, that such
election shall be subject to Company approval if made on or after the date that
triggers the Payment or a portion thereof): reduction of cash payments;
cancellation of accelerated vesting of Options; reduction of employee benefits.
If acceleration of vesting of Options is to be reduced, such acceleration of
vesting shall be cancelled in the reverse order of date of grant of Options
(i.e., earliest granted Option cancelled last) unless the Optionholder elects in
writing a different order for cancellation.

            For purposes of making the calculations required by this Section
11(e), the Accountant may make reasonable assumptions and approximations
concerning applicable taxes and may rely on reasonable, good faith
interpretations concerning the application of the Code and other applicable
legal authority. The Company and the Optionholder shall furnish to the
Accountant such information and documents as the Accountant may reasonably
request in order to make such a determination. The Company shall bear all costs
the Accountant may reasonably incur in connection with any calculations
contemplated by this Section 11(e).

                                      12.

<PAGE>

            If, notwithstanding any reduction described above, the Internal
Revenue Service (the "IRS") determines that the Optionholder is liable for the
Excise Tax as a result of the Payment, then the Optionholder shall be obligated
to pay back to the Company, within thirty (30) days after a final IRS
determination or, in the event that the Optionholder challenges the final IRS
determination, a final judicial determination, a portion of the Payment equal to
the "Repayment Amount." The Repayment Amount with respect to the Payment shall
be the smallest such amount, if any, as shall be required to be paid to the
Company so that the Optionholder's net after-tax proceeds with respect to the
Payment (after taking into account the payment of the Excise Tax and all other
applicable taxes imposed on the Payment) shall be maximized. The Repayment
Amount with respect to the Payment shall be zero if a Repayment Amount of more
than zero would not result in the Optionholder's net after-tax proceeds with
respect to the Payment being maximized. If the Excise Tax is not eliminated
pursuant to this paragraph, the Optionholder shall pay the Excise Tax.

            Notwithstanding any other provision of this Section 11(e), if (i)
there is a reduction in the Payment as described above, (ii) the IRS later
determines that the Optionholder is liable for the Excise Tax, the payment of
which would result in the maximization of the Optionholder's net after-tax
proceeds of the Payment (calculated as if the Payment had not previously been
reduced), and (iii) the Optionholder pays the Excise Tax, then the Company shall
pay or otherwise provide to the Optionholder that portion of the Payment that
was reduced pursuant to this Section 11(e) contemporaneously or as soon as
administratively possible after the Optionholder pays the Excise Tax so that the
Optionholder's net after-tax proceeds with respect to the Payment are maximized.

            If the Optionholder either (i) brings any action to enforce rights
pursuant to this Section 11(e), or (ii) defends any legal challenge to his or
her rights under this Section 11(e), the Optionholder shall be entitled to
recover attorneys' fees and costs incurred in connection with such action,
regardless of the outcome of such action; provided, however, that if such action
is commenced by the Optionholder, the court finds that the action was brought in
good faith.

12.   AMENDMENT OF THE PLAN AND OPTIONS.

      (a)   AMENDMENT OF PLAN. The Board, at any time and from time to time, may
amend the Plan. However, except as provided in Section 11 relating to
adjustments upon changes in Common Stock, no amendment shall be effective unless
approved by the stockholders of the Company to the extent stockholder approval
is necessary to satisfy the requirements of applicable laws.

      (b)   STOCKHOLDER APPROVAL. The Board, in its sole discretion, may submit
any other amendment to the Plan for stockholder approval.

      (c)   NO IMPAIRMENT OF RIGHTS. Rights 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 Optionholder and (ii) the
Optionholder consents in writing.

      (d)   AMENDMENT OF OPTIONS. 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 under any

                                      13.

<PAGE>

Option shall not be impaired by any such amendment unless (i) the Company
requests the consent of the Optionholder and (ii) the Optionholder consents in
writing.

13.   TERMINATION OR SUSPENSION OF THE PLAN.

      (a)   PLAN TERM. The Board may suspend or terminate the Plan at any time.
No Options 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 Option granted while the Plan is in
effect except with the written consent of the Optionholder.

14.   EFFECTIVE DATE OF PLAN.

      The Plan shall become effective on the IPO Date, but no Option 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.

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.

                                      14.

<PAGE>

                       VOLTERRA SEMICONDUCTOR CORPORATION
                 2004 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN

                            STOCK OPTION GRANT NOTICE
                           ([INITIAL] [ANNUAL] GRANT)

Volterra Semiconductor Corporation (the "Company"), pursuant to its 2004
Non-Employee Directors' Stock Option 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:      Nonstatutory Stock Option

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

VESTING SCHEDULE:   1/4th of the shares vest one year after the Vesting
                    Commencement Date.

                    1/16th of the shares vest quarterly thereafter over the next
                    three years.

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

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:
                                            ____________________________________
                                            ____________________________________

VOLTERRA SEMICONDUCTOR CORPORATION          OPTIONHOLDER:

By: ________________________________        ____________________________________
               Signature                                 Signature

Title: _____________________________        Date: ______________________________

Date:_______________________________

ATTACHMENTS: Stock Option Agreement, 2004 Non-Employee Directors' Stock Option
             Plan and Notice of Exercise

<PAGE>

                                  ATTACHMENT I

                             STOCK OPTION AGREEMENT

<PAGE>

                                  ATTACHMENT II

                 2004 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN

<PAGE>

                                 ATTACHMENT III

                               NOTICE OF EXERCISE

<PAGE>

                       VOLTERRA SEMICONDUCTOR CORPORATION
                 2004 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN

                             STOCK OPTION AGREEMENT
                           (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 Non-Employee Directors' Stock Option 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; and

            (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.

      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:

                                      1.

<PAGE>

                  (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.

      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;

                                       2.

<PAGE>

            (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;

            (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.

      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.

      9.    TRANSFERABILITY. Your option is transferable only by will or by the
laws of descent and distribution and is exercisable only by you during your
lifetime. However, you may transfer your option for no consideration upon
written consent of the Board (i) if, at the time of transfer, a Form S-8
registration statement under the Securities Act is available for the issuance of
shares by the Company upon the exercise of such transferred option or (ii) the
transfer is to your employer at the time of transfer or an affiliate of your
employer at the time of transfer. Any such transfer is subject to such limits as
the Board may establish, and subject to the transferee agreeing to remain
subject to all the terms and conditions applicable to your option prior to such
transfer. The forgoing right to transfer your option shall apply to the right to
consent to amendments to the Stock Option Agreement for such option. In
addition, until you transfers the option, you 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 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.

                                       3.

<PAGE>

      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 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.

                                       4.

<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:                             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):                $______________

      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
Non-Employee Directors' Stock Option Plan, and (ii) to provide for the payment
by me to you (in the manner designated by you) of your withholding obligation,
if any, relating to the exercise of this option.

--------------------------
(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>

                                                Very truly yours,
                                                ________________________________

                                       2.

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