##### Table of Contents



UNITED STATES SECURITIES AND
    EXCHANGE COMMISSIONWashington, DC
    20549
  Form 10-Q
   þ

QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d)
    OF THE SECURITIES EXCHANGE ACT OF 1934For the quarterly period ended
    March 31, 2006oro

TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
    SECURITIES EXCHANGE ACT OF 1934For the transition period
    from          
    to    Commission File Number
    000-50857
  Volterra Semiconductor
    Corporation
 (Exact name of registrant as
    specified in its charter)
  Delaware

94-3251865(State or other jurisdiction
    of
    incorporation or organization)

(I.R.S. Employer
    Identification No.)   3839
    Spinnaker Court
    Fremont, CA 94538 (Address
    of principal executive offices)
   Registrants telephone number, including area code:
 (510) 743-1200
   þ o
  Rule 12b-2
 o þ o
  Rule 12b-2 o þ




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Cautionary
    Note Regarding Forward-Looking Statements
  Form 10-Q Form 10-Q.




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##### 



VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
  
  PagePART I.
    FINANCIAL INFORMATION


1Item 1.

Financial
    Statements


1Condensed
    Consolidated Balance Sheets as of March 31, 2006 and
    December 31, 2005


1Condensed
    Consolidated Statements of Operations for the three months ended
    March 31, 2006 and 2005


2Condensed
    Consolidated Statements of Cash Flows for the three months ended
    March 31, 2006 and 2005


3Notes to the
    Condensed Consolidated Financial Statements


4Item 2.

Managements
    Discussion and Analysis of Financial Condition and Results of
    Operations


11Item 3.

Quantitative and
    Qualitative Disclosures about Market Risk


16Item 4.

Controls and
    Procedures


16PART II. OTHER
    INFORMATION


17Item 1.

Legal
    Proceedings


17Item 1A.

Risk Factors


17Item 6.

Exhibits


30SIGNATURES


31EXHIBIT 31.1EXHIBIT 31.2EXHIBIT 32.1EXHIBIT 32.2




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PART I.
    FINANCIAL INFORMATION  ITEM 1.
    Financial
    Statements  VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
 CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands, except share amounts)  March 31,


December 31,2006


2005(Unaudited)ASSETSCurrent assets:Cash and cash equivalents

$
36,571


$
32,955Short-term investments


9,991



14,952Accounts receivable, net of
    allowances of $726 and $654, respectively


12,937



8,711Inventory


4,739



4,283Prepaid expenses and other current
    assets


1,143



1,091Total current assets


65,381



61,992Property and equipment, net


3,625



3,477Other assets


70



34Total assets

$
69,076


$
65,503LIABILITIES AND
    STOCKHOLDERS EQUITYCurrent liabilities:Accounts payable

$
4,963


$
4,267Accrued liabilities


4,414



3,476Total current liabilities


9,377



7,743Commitments (note 4)Stockholders equity:Preferred stock, $0.001 par
    value; 5,000,000 shares authorized; none issued and
    outstanding






Common stock, $0.001 par
    value; 200,000,000 shares authorized; 23,932,299 and
    23,820,330 shares issued and outstanding, respectively


24



24Additional paid-in capital


97,459



96,227Deferred stock-based compensation






(189
)Accumulated deficit


(37,784
)


(38,302
)Total stockholders equity


59,699



57,760Total liabilities and
    stockholders equity

$
69,076


$
65,503  1




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VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per share amounts)

(Unaudited)  Three Months Ended
    March 31,2006


2005Net revenue

$
15,652


$
14,631Cost of revenue*


7,710



6,405Gross margin


7,942



8,226Operating expenses:Research and development*


5,178



3,625Selling, general and
    administrative*


2,585



2,132Total operating expenses


7,763



5,757Income from operations


179



2,469Interest and other income


485



252Interest and other expense


(20
)


(5
)Income before income taxes


644



2,716Income tax expense


127



407Net income

$
517


$
2,309Basic net income per share

$
0.02


$
0.10Shares used in computing basic net
    income per share


23,868



23,403Diluted net income per share

$
0.02


$
0.09Shares used in computing diluted
    net income per share


26,225



26,309(*) Includes stock-based
    compensation expense as follows:Cost of revenue

$
64


$
7Research and development


642



48Selling, general and administrative


495



64Total stock-based compensation

$
1,201


$
119  2




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VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
 CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

(Unaudited)  Three Months EndedMarch 31,2006


2005Cash flows from operating
    activities:Net income (loss)

$
517


$
2,309Adjustments to reconcile net
    income to net cash provided (used) by operating activities:Depreciation and amortization


330



129Accretion of discount in debt
    securities


116



Provision for doubtful accounts


(152
)


Stock-based compensation


1,201



119Changes in operating assets and
    liabilities:Accounts receivable


(4,073
)


(4,815
)Inventory


(407
)


(16
)Prepaid expenses, other current
    and other assets


(88
)


33Accounts payable


696



453Accrued liabilities


938



13Net cash used by operating
    activities


(922
)


(1,775
)Cash flows from investing
    activities:Purchases of property and equipment


(478
)


(874
)Purchases of short-term investments






(4,885
)Proceeds from maturity of
    short-term investments


4,845



4,949Net cash provided (used) by
    investing activities


4,367



(810
)Cash flows from financing
    activities:Proceeds from issuance of common
    stock, net


171



304Net cash provided by financing
    activities


171



304Net increase (decrease) in cash
    and cash equivalents


3,616



(2,281
)Cash and cash equivalents,
    beginning of period


32,955



24,895Cash and cash equivalents, end of
    period

$
36,571


$
22,614Supplemental disclosure of cash
    flows:Cash paid (refunded) for income
    taxes

$
(4
)

$
40Stock based compensation
    capitalized to inventory


49



  3




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VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
  NOTES TO
    CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
 (In thousands, except share and per share data)
 (Unaudited)
  1.
    Description
    of Business and Significant Accounting Policies    Basis
    of Presentation
    Form 10-K
    Use of
    Estimates
    Reclassifications
    Financial
    Instruments and Concentrations of Credit Risk
   4




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VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
  NOTES TO
    CONDENSED CONSOLIDATED FINANCIAL
    STATEMENTS  (Continued)
   held-to-maturity
  March 31,


December 31,2006


2005Amortized Cost

$
9,991


$
14,952Unrealized Gains






Unrealized Losses


(18
)


(33
)Fair Value

$
9,973


$
14,919       Segment
    Reporting and Significant Customers
      Net Revenue


Accounts ReceivableThree Months Ended


As ofMarch 31,


March 31,


December 31,Customer

2006


2005


2006


2005A


28
%


22
%


24
%


23
%B


21
%


11
%


13
%


10
%C


12
%


13
%


11
%


28
%D


10
%


*



*



*E


*



*



*



11
%F


*



13
%


*



*     *
    
    Less than 10% 5




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VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
  NOTES TO
    CONDENSED CONSOLIDATED FINANCIAL
    STATEMENTS  (Continued)
     Three Months Ended
    March 31,Geographic Area

2006


2005Singapore


50%



46%China


19%



20%Taiwan


9%



12%United States


8%



6%Thailand


7%



6%Japan


6%



6%Other


1%



4%     Revenue
    Recognition
      Earnings
    Per Share
   6




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VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
  NOTES TO
    CONDENSED CONSOLIDATED FINANCIAL
    STATEMENTS  (Continued)
     Three Months Ended
    March 31,2006


2005Numerator:Net income (in thousands)

$
517


$
2,309Denominator:Weighted average shares
    outstanding, basic


23,868,202



23,402,662Effect of dilutive securities:Stock options


2,357,129



2,906,032Weighted average shares
    outstanding, diluted


26,225,331



26,308,694Basic net income (loss) per share

$
0.02


$
0.10Diluted net income (loss) per share

$
0.02


$
0.09     Accounting
    for Stock-Based Compensation
  Share-Based Payment. Accounting for Stock Issued to
    Employees Accounting for Stock-Based Compensation.
     7




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VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
  NOTES TO
    CONDENSED CONSOLIDATED FINANCIAL
    STATEMENTS  (Continued)
    Stock Options


ESPPThree Months Ended
    March 31,


Three Months Ended
    March 31,2006


2005


2006


2005Expected Term (in years)


4.2-5.7



4.0



0.5



0.2Expected volatility


41
%


60
%


43
%


60
%Weighted-average volatility


41
%


60
%


43
%


60
%Risk-free interest rates


4.6
%


3.7
%


4.3
%


2.6
%Expected dividend














   paid-in-capital
    Three MonthsEndedMarch 31, 2006Stock-based compensation expense
    by type of award:Employee stock options

$
1,122Employee stock purchase plan


79Net change of amounts capitalized
    as inventory


49Total stock-based compensation


1,250Tax effect on stock-based
    compensation


Net effect on net income


1,250Effect on basic net income per
    share


(0.05
)Effect on diluted net income per
    share


(0.04
)  8




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##### Table of Contents



VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
  NOTES TO
    CONDENSED CONSOLIDATED FINANCIAL
    STATEMENTS  (Continued)
     Three MonthsEndedMarch 31, 2005Net income as reported

$
2,309Add: stock-based compensation for
    employee awards included in the determination of net income, net
    tax


101Deduct: stock-based compensation
    for employee awards determined under fair value method, net tax


(688
)Pro forma net income


1,722Basic net income per share:As reported


0.10Pro forma


0.07Diluted net income per shareAs reported


0.09Pro forma


0.07     WeightedWeighted-


Average


AggregateAverage


Remaining


IntrinsicShares


Exercise


Contractual


ValueOptions

(000)


Price


Years


($000)Outstanding at January 1, 2006


4,731



6.45Granted


621



18.53Exercised


(119
)


1.50Forfeited or expired


(18
)


7.00Outstanding at March 31, 2006


5,215



8.00



7.16



56,145Exercisable at March 31, 2006


2,762



4.03



5.60



40,715       Weighted-AverageShares


Grant-DateNon-Vested Options

(000)


Fair ValueOutstanding at January 1, 2006


2,101



4.62Granted


621



7.81Vested


(253
)


5.13Forfeited or expired


(16
)


8.48Outstanding at March 31, 2006


2,453



5.35    9




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VOLTERRA
    SEMICONDUCTOR CORPORATION AND SUBSIDIARIES
  NOTES TO
    CONDENSED CONSOLIDATED FINANCIAL
    STATEMENTS  (Continued)
   2.
    Inventory    March 31,


December 31,2006


2005Work-in-process

$
2,705


$
2,219Finished goods


2,034



2,064$
4,739


$
4,283   3.
    Property
    and Equipment    March 31,


December 31,2006


2005Computer hardware

$
1,370


$
999Computer software


4,279



4,244Equipment and furniture


2,221



2,155Leasehold improvements


634



6348,504



8,032Less accumulated depreciation and
    amortization


(4,879
)


(4,555
)$
3,625


$
3,477   4.
    Commitments      2010 and2006


2007


2008


2009


Thereafter


TotalFuture minimum lease commitments

$
409


$
395


$
73


$
24


$



$
901Inventory purchase commitments


4,214



















4,214$
4,623


$
395


$
73


$
24


$



$
5,115    10




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##### Table of Contents



Item 2.
    Managements
    Discussion and Analysis of Financial Condition and Results of
    Operations  Form 10-Q.
  Overview
        Three Months EndedMar. 31,


Dec. 31,


Sep. 30,


Jun. 30,


Mar. 31,2006


2005


2005


2005


2005Net revenue (in thousands)

$
15,652


$
13,541


$
12,509


$
13,185


$
14,631As a percent of net revenue:GAAP Gross margin


51
%


51
%


53
%


59
%


56
%Add: Stock-based compensation


*
%


*
%


*
%


*
%


*
%Non-GAAP Gross margin


51
%


51
%


53
%


59
%


56
%GAAP Income from operations


1
%


9
%


5
%


9
%


17
%Add: Stock-based compensation


8
%


(1
)%


*
%


1
%


1
%Non-GAAP Income from
    operations


9
%


8
%


5
%


10
%


18
%     *
    
    Stock-based compensation did not have an effect as a percent of
    revenue.   11




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12




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##### Table of Contents



Net Revenue.
  Cost of Revenue.
  Research and Development.
  Selling, General and
    Administrative.
  Income Taxes.
  Critical
    Accounting Policies
  Form 10-K,
  Accounting for Stock Appreciation
    Rights and Other Variable Stock Option or Awards Plans.
   13




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Results
    of Operations
    Three Months EndedMarch 31,2006


2005Net revenue


100
%


100
%Cost of revenue


49



44Gross margin


51



56Operating expenses:Research and development


33



24Selling, general and administrative


17



15Total operating expenses


50



39Income from operations


1



17Interest and other income, net


3



2Income before income taxes


4



19Income tax expense


1



3Net Income


3
%


16
%   Comparison
    of Quarter Ended March 31, 2006 to Quarter Ended
    March 31, 2005
  Net Revenue.
  Cost of Revenue and Gross Margin.
 14




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##### Table of Contents



Research and Development.
  Selling, General and
    Administrative.
  Income Tax Expense.
  Liquidity
    and Capital Resources
          Contractual
    Obligations
   15




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##### Table of Contents



2010 and2006


2007


2008


2009


Thereafter


TotalFuture minimum lease commitments

$
409


$
395


$
73


$
24


$



$
901Inventory purchase commitments


4,214



















4,214$
4,623


$
395


$
73


$
24


$



$
5,115     Recent
    Accounting Pronouncements
  Share-Based Payment
  Item 3.
    Quantitative
    and Qualitative Disclosures About Market Risk      Item 4.
    Controls
    and Procedures  Evaluation
    of Disclosure Controls and Procedures
  Rules 13a-15(e) 15d-15(e) Rules 13a-15(b) 15d-15(b)
   16




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##### Table of Contents



PART II.
    OTHER INFORMATION  Item 1.
    Legal
    Proceedings    Item 1A.
    Risk
    Factors  Form 10-Q.
  We are an
    early stage semiconductor company with a limited operating
    history, which makes it difficult to evaluate our current
    business and future prospects and may increase the risk of your
    investment.
    
    we have limited historical financial data from which to predict
    our future revenue and operating results;
    we are subject to the highly cyclical nature of, and downturns
    in, the semiconductor industry;
    we depend on a small number of customers for substantially all
    of our net revenue;
    we have a limited number of products; and
    we may face difficulties in managing growth in personnel and
    operations.    We have a
    history of losses, have only recently experienced revenue growth
    and become profitable and may not maintain profitability on a
    quarterly or annual basis.
   17




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##### Table of Contents



Our
    operating results have fluctuated in the past, and we expect a
    number of factors to cause our operating results to fluctuate in
    the future, making it difficult for us to accurately forecast
    our operating results.
    
    changes in orders received and shipped during the quarter, or
    our turns business, which is difficult to forecast and
    represents an increasing percentage of our net revenue;
    the loss of one or more key customers, or a significant
    reduction in sales to one or more key customers;
    our customers failure to pay us on a timely basis, or at
    all;
    varying order patterns in the markets in which we sell our
    products;
    demand for our products or the electronic systems into which our
    products are incorporated;
    our customers and distributors management of the
    inventory they hold;
    our ability to develop new products or new generations and
    versions of our existing products that achieve market acceptance
    in a timely manner;
    the ability of our foundries and third-party subcontractors to
    achieve satisfactory yields or quality;
    our ability to obtain sufficient capacity from foundries and
    other third-party subcontractors to manufacture, assemble and
    test our products on a timely and cost-effective basis;
    the ability of our manufacturing subcontractors to obtain an
    adequate supply of the raw materials used in the manufacture of
    our products on a timely and cost-effective basis;
    the cyclical nature of the semiconductor industry;
    changes in the level of our expenses, including the cost of
    materials used to manufacture our products;
    the loss of one or more key distributors, or a significant
    reduction in orders from one or more key distributors;
    the timing of introductions of competing products or
    technologies;
    our ability to fulfill orders for our products in a timely
    manner, or at all;
    changes in the prices of our products or the electronic systems
    into which our products are incorporated;
    our ability to adequately support our future growth;
    disputes regarding intellectual property rights;
    litigation involving us or our products; and
    changes in accounting principles or policies, including the
    requirement to treat employee stock option grants as an
    operating expense   18




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##### Table of Contents



We depend
    on a small number of customers for substantially all of our net
    revenue and the loss of, or a significant reduction in orders
    from, any of them would significantly reduce our net revenue and
    adversely affect our operating results.
    We depend
    on a limited number of markets, and in these markets we have
    experienced varying order patterns, and if demand for our
    products in these markets declines, or if we are unable to
    adjust to the varying order patterns in these markets or expand
    into new markets, our business would be harmed.
      We sell a
    limited number of products and a reduction in demand for these
    products would harm our business and operating
    results.
    If we are
    unable to timely develop new products or new generations and
    versions of our existing products that achieve market
    acceptance, our operating results and competitive position could
    be harmed.
   19




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##### Table of Contents




    our accurate prediction of changing customer requirements;
    timely development of new designs;
    timely qualification and certification of our products for use
    in electronic systems;
    commercial acceptance and production of the electronic systems
    into which our products are incorporated;
    availability, quality, price, performance, and size of our
    products relative to competing products and technologies;
    our customer service and support capabilities and responsiveness;
    successful development of relationships with existing and
    potential new customers;
    successful development of relationships with key developers of
    advanced digital semiconductors; and
    changes in technology, industry standards or consumer
    preferences.    We have
    experienced, and may in the future experience, delays in the
    development and introduction of our products, which may harm our
    business and operating results.
    Our
    products are highly complex and may require modifications to
    resolve undetected errors or failures and to meet our
    customers specifications, which could lead to an increase
    in our costs, a loss of customers, a delay in market acceptance
    of our products, or product liability claims.
   20




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##### Table of Contents



Our
    dependence on third-party semiconductor manufacturers, or
    foundries, reduces our control over the manufacture of our
    products, which could harm our business.
    
    inability to increase production and achieve acceptable yields
    on a timely basis;
    reduced control over delivery schedules and product quality;
    inability of our foundries to obtain an adequate supply of the
    raw materials used in the manufacturing of our products on a
    timely and cost-effective basis;
    increased exposure to potential misappropriation of our
    intellectual property;
    limited warranties on silicon wafers or products supplied to us;
    labor shortages or labor strikes;
    natural disasters affecting countries in which we conduct our
    business or in which our products are manufactured; and
    political instability in countries where our products are
    manufactured.    We rely
    on third-party subcontractors to assemble and test our products
    and our failure to successfully manage our relationships with
    these subcontractors could damage our relationships with our
    customers, decrease our net revenue, and limit our
    growth.
   21




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##### Table of Contents



If our
    foundries and assembly and test subcontractors fail to achieve
    satisfactory yields or quality, our revenue and operating
    results could decrease, and our relationships with our customers
    and our reputation may be harmed.
    We are
    subject to the highly cyclical nature of the semiconductor
    industry and any future downturns could significantly harm our
    business.
    We rely
    primarily on a small number of distributors to market and
    distribute our products, and if we fail to maintain or expand
    these relationships, our net revenue would likely
    decline.
        The
    nature of the design process requires us to incur expenses prior
    to earning revenue associated with those expenses, and we will
    have difficulty selling our products and generating profits if
    system designers do not design our products into their
    electronic systems.
   22




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##### Table of Contents




    it can take up to 12 months or longer from the time our
    products are selected to complete the design process;
    it can take an additional six to 12 months or longer to
    complete commercial introduction of the electronic systems that
    use our products, if they are introduced at all;
    our customers usually require a comprehensive technical
    evaluation of our products before they incorporate them into
    their electronic systems;
    OEMs typically limit the initial release of their electronic
    systems to evaluate performance and consumer demand; and
    the development and commercial introduction of products
    incorporating new technology are frequently delayed.    We face
    significant competition and many of our competitors have greater
    resources than we have, and thus we may be unsuccessful in
    competing against current and future competitors.
    
    our ability to continue to recruit and retain engineering talent;
    our ability to introduce new products in a timely manner;
    the pricing of components used in competing solutions;
    the pace at which our customers incorporate our products into
    their systems;
    the availability of foundry, assembly, and test capacity for our
    products;
    protection of our products by effective utilization of
    intellectual property laws; and
    general economic conditions.     23




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##### Table of Contents



Any
    disruption to our operations or the operations of our foundries
    or assembly and test subcontractors resulting from earthquakes,
    droughts, or other natural disasters or public health issues
    could significantly delay the production or shipment of our
    products.
    The
    average selling prices of our products could decrease rapidly,
    which may negatively impact our net revenue and operating
    results.
    We are
    subject to inventory risks and manufacturing costs that could
    negatively impact our operating results.
   24




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##### Table of Contents



We have
    significant international activities and customers, and plan to
    continue such efforts, which subjects us to additional business
    risks including increased logistical complexity, political
    instability, and currency fluctuations.
    
    cultural and language barriers;
    increased complexity and costs of managing international
    operations;
    protectionist laws and business practices that favor local
    competition in some countries;
    multiple, conflicting and changing laws and regulatory and tax
    environments, including the European Unions Restrictions
    of Hazardous Substances (RoHS), which bans lead and
    certain other substances from products put on the market;
    potentially longer and more difficult collection periods;
    political instability, international terrorism, and
    anti-American
    sentiment, particularly in emerging markets;
    highly volatile economies in Asia;
    difficulty in hiring qualified management, technical sales
    personnel, and applications engineers; and
    less effective protection of intellectual property than is
    afforded to us in the United States.      Environmental
    laws and regulations could cause a disruption in our business
    and operations.
   25




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##### Table of Contents



We rely
    on the services of our key personnel, and if we are unable to
    retain our current personnel and hire additional personnel, our
    ability to develop and successfully market our products could be
    harmed.
    If we do
    not effectively manage our growth, our resources, systems, and
    controls may be strained and our operating results may
    suffer.
     26




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Our
    ability to compete will be harmed if we are unable to adequately
    protect our intellectual property.
    Assertions
    by third parties of infringement by us of their intellectual
    property rights could result in significant costs and cause our
    operating results to suffer.
    
    stop selling products or using technology that contain the
    allegedly infringing intellectual property;
    pay damages to the party claiming infringement;
    attempt to obtain a license to the relevant intellectual
    property, which may not be available on reasonable terms or at
    all; and
    attempt to redesign those products that contain the allegedly
    infringing intellectual property.    Any
    potential dispute involving our patents or other intellectual
    property could also include our customers, which could trigger
    our indemnification obligations to them and result in
    substantial expense to us.
    We may
    need to raise additional capital, which might not be available
    or which, if available, may be on terms that are not favorable
    to us.
   27




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##### Table of Contents



We may
    undertake acquisitions to expand our business that may pose
    risks to our business and dilute the ownership of our existing
    stockholders.
    
    our lack of experience acquiring other businesses;
    problems integrating the acquired operations, technologies, or
    products with our existing business and products;
    diversion of managements time and attention from our core
    business;
    the need for financial resources above our planned investment
    levels;
    overestimation of potential synergies or a delay in realizing
    those synergies;
    difficulties in retaining business relationships with suppliers
    and customers of the acquired company;
    risks associated with entering markets in which we lack prior
    experience; and
    the potential loss of key employees of the acquired company.    Our stock
    price will fluctuate and may be volatile, which could result in
    substantial losses for investors and significant costs related
    to litigation.
    
    actual or anticipated fluctuations in our revenue, operating
    results or growth rate;
    failure to meet the expectations of securities analysts or
    investors with respect to our financial performance;
    actual or anticipated fluctuations in our competitors
    operating results or changes in their growth rates;
    sales of our common stock or other securities in the future;
    stock market price and trading volume fluctuations of
    publicly-traded companies in general and semiconductor companies
    in particular;
    the trading volume of our common stock;
    changes in financial estimates and ratings by securities
    analysts for us, our competitors or companies in the
    semiconductor industry generally; 28




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##### Table of Contents




    changes in the condition of the financial markets, the economy
    as a whole, the semiconductor industry, our customers or our
    competitors;
    publicity about the semiconductor industry, our competitors or
    our customers; and
    additions or departures of key personnel.      Our
    principal stockholders have significant voting power and may
    influence actions that may not be in the best interests of our
    other stockholders.
    Anti-takeover
    provisions of our charter documents and Delaware law could
    prevent or delay transactions resulting in a change in
    control.
    
    our board of directors is classified so that not all members of
    our board may be elected at one time;
    directors may only be removed for cause and only
    with the approval of stockholders holding a majority of our
    outstanding voting stock;
    the ability of our stockholders to call a special meeting of
    stockholders is prohibited;
    advance notice requirements for nominations for election to our
    board of directors or for proposing matters that can be acted
    upon at stockholder meetings;
    stockholder action by written consent is prohibited, thereby
    requiring all stockholder actions to be taken at a meeting of
    our stockholders; and
    our board of directors may designate the terms of and issue new
    series of preferred stock, commonly referred to as blank
    check preferred stock, with rights senior to those of
    common stock without stockholder approval.   29




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##### Table of Contents



Item 6.
    Exhibits  ExhibitNo.

Description3
.1(1)

Amended and Restated Certificate
    of Incorporation of Volterra Semiconductor Corporation.3
.2(2)

Amended and Restated Bylaws of
    Volterra Semiconductor Corporation.4
.1

Reference is made to
    Exhibits 3.1 and 3.2.4
.2(3)

Specimen stock certificate.10
.1(4)

2006 Management Bonus Plan.31
.1

Certification of Chief Executive
    Officer required under
    Rule 13a-14(a)
    or
    Rule 15d-14(a)
    of the Securities Exchange Act of 1934, as amended.31
.2

Certification of Chief Financial
    Officer required under
    Rule 13a-14(a)
    or
    Rule 15d-14(a)
    of the Securities Exchange Act of 1934, as amended.32
.1*

Certification of Chief Executive
    Officer required under
    Rule 13a-14(b)
    or
    Rule 15d-14(b)
    of the Securities Exchange Act of 1934, as amended, and
    18 U.S.C. Section 1350.32
.2*

Certification of Chief Financial
    Officer required under
    Rule 13a-14(b)
    or
    Rule 15d-14(b)
    of the Securities Exchange Act of 1934, as amended, and
    18 U.S.C. Section 1350.     (1)
    
    Previously filed as Exhibit 3.1 to Volterra Semiconductor
    Corporations Quarterly Report on
    Form 10-Q
    for the quarterly period ended June 30, 2004, as filed with
    the Securities and Exchange Commission on September 9,
    2004, and incorporated by reference herein.(2)
    
    Previously filed as Exhibit 3.4 to Volterra Semiconductor
    Corporations Registration Statement on
    Form S-1
    (No. 333-115614),
    as filed with the Securities and Exchange Commission on
    May 19, 2004, as amended, and incorporated by reference
    herein.(3)
    
    Previously filed as Exhibit 4.2 to Volterra Semiconductor
    Corporations Registration Statement on
    Form S-1/A
    (No. 333-115614),
    as filed with the Securities and Exchange Commission on
    July 9, 2004, as amended, and incorporated by reference
    herein.(4)
    
    Previously filed as Exhibit 10.1 to Volterra Semiconductor
    Corporations Current Report on
    Form 8-K,
    as filed with the Securities and Exchange Commission on
    February 9, 2006, and incorporated by reference herein.*
    
    The certifications attached as Exhibits 32.1 and 32.2
    accompany this Quarterly Report on
    Form 10-Q
    pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
    and shall not be deemed filed by Volterra
    Semiconductor Corporation for purposes of Section 18 of the
    Securities Exchange Act of 1934, as amended. 30




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##### Table of Contents



SIGNATURE      By:
    /s/  GREG
    HILDEBRAND     Chief Financial Officer
  (Principal Financial, Chief Accounting and
  Duly Authorized Officer)
   31




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##### Table of Contents



EXHIBIT INDEX
  ExhibitNo.

Description3
.1(1)

Amended and Restated Certificate
    of Incorporation of Volterra Semiconductor Corporation.3
.2(2)

Amended and Restated Bylaws of
    Volterra Semiconductor Corporation.4
.1

Reference is made to
    Exhibits 3.1 and 3.2.4
.2(3)

Specimen stock certificate.10
.1(4)

2006 Management Bonus Plan.31
.1

Certification of Chief Executive
    Officer required under
    Rule 13a-14(a)
    or
    Rule 15d-14(a)
    of the Securities Exchange Act of 1934, as amended.31
.2

Certification of Chief Financial
    Officer required under
    Rule 13a-14(a)
    or
    Rule 15d-14(a)
    of the Securities Exchange Act of 1934, as amended.32
.1*

Certification of Chief Executive
    Officer required under
    Rule 13a-14(b)
    or
    Rule 15d-14(b)
    of the Securities Exchange Act of 1934, as amended, and
    18 U.S.C. Section 1350.32
.2*

Certification of Chief Financial
    Officer required under
    Rule 13a-14(b)
    or
    Rule 15d-14(b)
    of the Securities Exchange Act of 1934, as amended, and
    18 U.S.C. Section 1350.     (1)
    
    Previously filed as Exhibit 3.1 to Volterra Semiconductor
    Corporations Quarterly Report on
    Form 10-Q
    for the quarterly period ended June 30, 2004, as filed with
    the Securities and Exchange Commission on September 9,
    2004, and incorporated by reference herein.(2)
    
    Previously filed as Exhibit 3.4 to Volterra Semiconductor
    Corporations Registration Statement on
    Form S-1
    (No. 333-115614),
    as filed with the Securities and Exchange Commission on
    May 19, 2004, as amended, and incorporated by reference
    herein.(3)
    
    Previously filed as Exhibit 4.2 to Volterra Semiconductor
    Corporations Registration Statement on
    Form S-1/A
    (No. 333-115614),
    as filed with the Securities and Exchange Commission on
    July 9, 2004, as amended, and incorporated by reference
    herein.(4)
    
    Previously filed as Exhibit 10.1 to Volterra Semiconductor
    Corporations Current Report on
    Form 8-K,
    as filed with the Securities and Exchange Commission on
    February 9, 2006, and incorporated by reference herein.*
    
    The certifications attached as Exhibits 32.1 and 32.2
    accompany this Quarterly Report on
    Form 10-Q
    pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
    and shall not be deemed filed by Volterra
    Semiconductor Corporation for purposes of Section 18 of the
    Securities Exchange Act of 1934, as amended.