SUPX Supertex, Inc. (MM)

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS

TO BE HELD ON [                      ], 2014

Dear Shareholder:

You are cordially invited to attend the Special Meeting of Shareholders of Supertex, Inc., a California corporation, or Supertex, that will be held at our offices at 1235 Bordeaux Drive, Sunnyvale California 94089, at 10:00 a.m., local time, on [                      ], 2014, or the Special Meeting, for the following purposes:

Microchip Technology Incorporated is a Delaware corporation. Orchid Acquisition Corporation is a California corporation and is a wholly-owned subsidiary of Microchip Technology Incorporated.

Our board of directors reviewed and considered the terms and conditions of the Merger and determined that the Merger and the Merger Agreement are fair to, and in the best interests of, Supertex and our shareholders, declared the Merger Agreement and the transactions contemplated thereby, including the Merger, to be advisable and recommended that Supertex shareholders vote to approve the Merger Proposal. This item of business to be submitted to a vote of the shareholders at the Special Meeting is more fully described in the attached proxy statement, which we urge you to read carefully. Our board of directors also recommends that you approve the Advisory Compensation Proposal and the Adjournment Proposal. No other business may be transacted at the Special Meeting.

Shareholders of record at the close of business on the record date, February 24, 2014, are entitled to notice of and to vote at the Special Meeting and any adjournment or postponement of the meeting. The proxy statement is dated [                      ], 2014, and is first being mailed to shareholders of Supertex on or about [                      ], 2014. All shareholders are cordially invited to attend the Special Meeting in person. Approval of the Merger Proposal will require the affirmative vote of the holders of a majority of the outstanding shares of Supertex common stock as of the record date. Approval of the Advisory Compensation Proposal and the Adjournment Proposal will each require the affirmative vote of the holders of a majority of the shares of Supertex common stock present, in person or by proxy, at the Special Meeting, excluding abstentions.

Supertex shareholders have the right to exercise dissenters’ rights with respect to their shares of Supertex common stock and may have the right to obtain payment in cash for the fair market value of their shares of Supertex common stock, but only if they perfect their dissenters’ rights and comply with the applicable provisions of California law. A copy of the California statutory provisions relating to dissenters’ rights is attached as Annex D to the attached proxy statement, and a summary of these provisions can be found under “The Merger—Dissenters’ Rights” in the attached proxy statement.

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You should not send any certificates representing shares of Supertex common stock with your proxy card. Upon the closing of the Merger, you will be sent instructions regarding the procedure to exchange your stock certificates for the cash Merger Consideration.

OUR BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE “FOR”

(1) THE APPROVAL OF THE PRINCIPAL TERMS OF THE MERGER AND

THE ADOPTION OF THE MERGER AGREEMENT, (2) THE APPROVAL, ON AN ADVISORY

(NON-BINDING) BASIS, OF CERTAIN OF THE COMPENSATION THAT MAY BE PAID OR

BECOME PAYABLE TO OUR NAMED EXECUTIVE OFFICERS THAT IS BASED ON OR

OTHERWISE RELATES TO THE MERGER, AS WELL AS THE AGREEMENTS PURSUANT TO

WHICH SUCH COMPENSATION MAY BE PAID OR BECOME PAYABLE AND (3) THE GRANT

OF AUTHORITY TO VOTE YOUR SHARES TO

ADJOURN THE SPECIAL MEETING, IF NECESSARY, FOR THE PURPOSE OF SOLICITING

ADDITIONAL PROXIES TO VOTE IN FAVOR OF APPROVING THE PRINCIPAL TERMS OF

THE MERGER AND ADOPTING THE MERGER AGREEMENT.

YOUR VOTE IS IMPORTANT.

Your vote is very important, regardless of the number of shares you own. Even if you plan to attend the Special Meeting in person, we request that you complete, sign, date and return your proxy card in the enclosed envelope, or appoint a proxy over the Internet or by telephone as instructed in these materials, to ensure that your shares will be represented at the Special Meeting if you are unable to attend. If you sign, date and mail your proxy card without indicating how you wish to vote, your proxy will be counted as a vote in favor of the Merger Proposal, in favor of the Advisory Compensation Proposal, and in favor of the Adjournment Proposal. If you fail to return your proxy card or if you fail to appoint a proxy over the Internet or by telephone, your shares will not be counted for purposes of determining whether a quorum is present at the Special Meeting and will have the same effect as a vote against approving the Merger Proposal. If you do attend the Special Meeting and wish to vote in person, you may withdraw your proxy and vote in person. If your shares are held of record in the name of your broker, bank or other nominee, you must obtain a proxy, executed in your favor, from the holder of record to be able to vote in person at the Special Meeting.

No person has been authorized to give any information or to make any representations other than those set forth in the proxy statement in connection with the solicitation of proxies made hereby, and, if given or made, such information must not be relied upon as having been authorized by Supertex or any other person.

By Order of the Board of Directors

Henry C. Pao

President and Chief Executive Officer

Sunnyvale, California

[                      ], 2014

THIS TRANSACTION HAS NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES

AND EXCHANGE COMMISSION NOR HAS THE SECURITIES AND EXCHANGE

COMMISSION PASSED UPON THE FAIRNESS OR MERITS OF SUCH TRANSACTION NOR

UPON THE ACCURACY OR ADEQUACY OF THE INFORMATION CONTAINED IN THIS

DOCUMENT. ANY REPRESENTATION TO THE CONTRARY IS UNLAWFUL.

In addition to delivering the proxy materials for the Special Meeting to be held on [                      ], 2014 to shareholders by mail, the proxy statement for such meeting is also is available at w ww.supertex.com .

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SUMMARY TERM SHEET

This Summary Term Sheet, together with the “Questions and Answers About the Special Meeting and Merger,” summarizes the material information in the proxy statement. You should carefully read this entire proxy statement and the other documents to which this proxy statement refers you for a more complete understanding of the matters being considered at the Special Meeting. In addition, you may obtain additional business and financial information about Supertex, Inc. without charge by following the instructions in “Where You Can Find More Information” beginning on page 72. We have included page references in parentheses to direct you to more complete descriptions of the topics presented in this summary. Attached as Annex A to this proxy statement is the Agreement and Plan of Merger, dated as of February 9, 2014, among Microchip Technology Incorporated, Orchid Acquisition Corporation and Supertex, Inc., or the Merger Agreement. We encourage you to read the Merger Agreement, as it is the legal document that governs the merger, or the Merger. In this proxy statement, “we,” “us,” “our” and “Supertex” refer to Supertex, Inc. and, including, where applicable, our subsidiaries.

The Merger and the Merger Agreement.

The Parties to the Merger (see page 14 ) . Supertex, Inc., a California corporation, is a leading provider of high voltage and mixed signal semiconductor components, including integrated circuits. Microchip Technology Incorporated, a Delaware corporation, or Parent or Microchip, is a leading provider of microcontroller and analog semiconductors. Orchid Acquisition Corporation, a California corporation and a wholly-owned subsidiary of Parent, or Merger Sub, has not engaged in any business except for the purpose of effecting the Merger.

The Merger . You are being asked to vote to approve the principal terms of the Merger and adopt the Merger Agreement, or the Merger Proposal. Pursuant to the Merger Agreement, Merger Sub will merge with and into Supertex with Supertex being the surviving corporation in the Merger, such surviving corporation hereinafter referred to as the “Surviving Corporation”. As a result of the Merger, Supertex will cease to be an independent, publicly-traded company. You will no longer have any interest in Supertex’s future earnings or growth. Following consummation of the Merger, the registration of Supertex common stock and our reporting obligations with respect to our common stock under the Securities Exchange Act of 1934, as amended, or the Exchange Act, will be terminated upon application to the Securities and Exchange Commission, or the SEC. In addition, upon completion of the Merger, shares of our common stock will no longer be listed on any stock exchange, including the NASDAQ Global Market, or quotation system. See “The Merger Agreement” beginning on page 51.

Merger Consideration . If the Merger is consummated, you will be entitled to receive $33.00, or the Merger Consideration, in cash, without interest and less any applicable withholding taxes, for each share of Supertex common stock that you own (other than shares as to which dissenters’ rights have been properly exercised). See “The Merger Agreement—Merger Consideration” beginning on page 52.

Treatment of Options (see page 52) . Upon the consummation of the Merger, all outstanding vested options (that is, options then exercisable) to acquire our common stock will be cancelled. In consideration for the cancellation of the options, the holder of any such option will receive an amount equal to the number of shares of our common stock underlying the option multiplied by the amount (if any) by which $33.00 exceeds the exercise price for each share of Supertex common stock underlying the options, without interest and less any applicable withholding taxes. If the exercise price of the vested option is equal to or exceeds $33.00, the holder of such option will not be entitled to any Merger Consideration. All outstanding unvested options will be assumed by Parent and remain subject to substantially the same terms and conditions, except that: (1) the number of shares of Parent common stock subject to each such outstanding unvested option will be equal to the product of the number of shares of our common stock underlying such option and the Exchange Ratio (as defined in “Interests of Directors and Executive Officers in the Merger Agreement—Treatment of Stock Options” beginning on page 32), rounded down to the nearest whole share, and (2) the exercise price of each such outstanding unvested option will be equal to the quotient determined by dividing the exercise price by the Exchange Ratio, rounded up to the nearest cent.

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Treatment of Employee Stock Purchase Plan (see page 53) . The offering period underway under our Employee Stock Purchase Plan at the time of the Merger will be shortened and terminate on either the last business day or the last payroll date prior to the consummation of the Merger and Supertex will make such pro-rata adjustments as necessary to reflect such shortened offering period, but will otherwise treat such shortened offering period as a fully effective and completed offering period for all other purposes. Supertex will provide that no additional offering periods commence under the plan after March 31, 2014 and the Supertex Employee Stock Purchase Plan will terminate prior to the consummation of the Merger.

Conditions to the Merger (see page 60) . The consummation of the Merger depends on the satisfaction or waiver of a number of conditions, including the following:

the Merger Agreement must have been adopted and the principal terms of the Merger must have been approved by the affirmative vote of the holders of a majority of the outstanding shares of Supertex common stock as of the record date, February 24, 2014;

any applicable waiting period (and any extension thereof) under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, or the HSR Act, must have expired or been terminated;

no governmental entity of competent jurisdiction must have enacted, issued, promulgated, entered or enforced any law that is in effect and has the effect of making the Merger illegal in any jurisdiction or which has the effect of prohibiting or otherwise preventing the consummation of the Merger in any jurisdiction, and no court of competent jurisdiction must have issued or granted any order (whether temporary, preliminary or permanent) that has the effect of making the Merger illegal in any jurisdiction or which has the effect of prohibiting or otherwise preventing the consummation of the Merger in any jurisdiction;

there must not have been any Company Material Adverse Effect (as defined in “The Merger Agreement—Representations and Warranties” beginning on page 53) upon Supertex;

Supertex’s, Parent’s and Merger Sub’s respective representations and warranties in the Merger Agreement must be true and correct as of the date of the Merger Agreement and on and as of the date of the closing of the Merger in the manner described under the caption “The Merger Agreement—Conditions to the Merger” beginning on page 60; and

Supertex, Parent and Merger Sub must have performed or complied with in all material respects all obligations under the Merger Agreement that each is required to perform or comply with at or prior to the closing of the Merger.

Restrictions on Solicitations of Other Offers and the Recommendation of our Board of Directors (see pages  62 and 20 ) .

The Merger Agreement provides that we must cause each of our company representatives to immediately cease any existing activities, discussions or negotiations with any third party conducted prior to the execution of the Merger Agreement with respect to an Acquisition Proposal (as defined in “The Merger Agreement—Restrictions on Solicitations of Other Offers” beginning on page 62) and, until the consummation of the Merger or its earlier termination, we are generally not permitted to:

solicit, initiate, knowingly encourage or facilitate the making, submission or announcement of, an Acquisition Proposal;

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furnish to any third party (other than Parent, Merger Sub or any designees of Parent or Merger Sub) any non-public information relating to us or any of our subsidiaries that we believe or reasonably expect could be used for the purposes of making, submitting or announcing an Acquisition Proposal, or afford access to our business, properties, assets, books or records to any third party (other than Parent, Merger Sub or any designees of Parent or Merger Sub) that we believe or reasonably expect could be used for the purposes of making, submitting or announcing an Acquisition Proposal, or take any other action intended to assist or facilitate any inquiries or the making of any proposal that constitutes or would be reasonably expected to lead to an Acquisition Proposal;

participate or engage in discussions or negotiations with any third party with respect to an Acquisition Proposal;

approve, endorse or recommend an Acquisition Proposal;

execute or enter into any letter of intent, memorandum of understanding or contract contemplating or otherwise relating to an Acquisition Transaction (as defined in “The Merger Agreement—Restrictions on Solicitations of Other Offers” beginning on page 62); or

terminate, amend, modify, waive or fail to enforce any rights under any “standstill” or other similar agreement between us or any of our subsidiaries and any third party (other than Parent).

The Merger Agreement provides that (subject to certain exceptions) neither our board of directors nor any of its committees may:

withhold, withdraw, amend or modify in a manner adverse to Parent our board of directors’ recommendation to our shareholders that they approve the principal terms of the Merger and adopt the Merger Agreement;

approve or recommend any Acquisition Proposal of a third party; or

cause or permit Supertex to enter into (or publicly propose that Supertex enter into) any alternative acquisition agreement with respect to any Acquisition Proposal.

Notwithstanding these restrictions, under certain circumstances, and so long as Supertex complies with certain terms of the Merger Agreement described under “The Merger Agreement—Restrictions on Solicitations of Other Offers” and “The Merger Agreement—Recommendation and Recommendation Change,” our board of directors may (1) respond to a bona fide unsolicited Acquisition Proposal not obtained in violation of our covenants in the Merger Agreement which our board of directors reasonably concludes in good faith after consultation with its financial advisors and outside legal counsel constitutes or is reasonably likely to lead to a Superior Proposal (as defined in “The Merger Agreement—Restrictions on Solicitations of Other Offers”), (2) approve or recommend certain Superior Proposals and, in connection with such approval or recommendation, withdraw or modify its recommendation of the Merger Agreement and/or terminate the Merger Agreement, and/or (3) withdraw or modify our board of directors’ recommendation of the Merger Agreement in response to a material development occurring after the date of the Merger Agreement that was neither known by our board of directors or reasonably foreseeable, where our board of directors determines in good faith, after consultation with its outside legal counsel, that failure to take such action would reasonably be expected to result in a breach of its fiduciary duties to our shareholders.

Termination of the Merger Agreement (see page 64 ) . The Merger Agreement may be terminated:

by mutual written consent of Supertex and Parent;

by either Supertex or Parent, if:

the Merger is not consummated on or before July 14, 2014, unless the failure of the Merger to be consummated by such date is primarily caused by the failure of the party seeking to exercise such termination right to fulfill any obligation under the Merger Agreement;

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any governmental entity having jurisdiction over Supertex, Parent or Merger Sub has issued a final and non-appealable order, decree or ruling or taken any other action, in each case permanently enjoining or otherwise prohibiting the consummation of the Merger; or

the Special Meeting concludes without the approval by our shareholders of the Merger Agreement in accordance with the California Corporations Code, or the CCC;

by Parent, if:

we breach any of our covenants or agreements in the Merger Agreement or if any of our representations and warranties in the Merger Agreement were inaccurate when made or become inaccurate, and such breach or inaccuracy (i) would give rise to the failure of a condition to Parent’s or Merger Sub’s obligation to consummate the Merger and (ii) if curable by the exercise of our commercially reasonable efforts, is not cured within 30 days or by July 14, 2014 after delivery of written notice to us of such breach or inaccuracy;

we breach (or are deemed to have breached) the restrictions on solicitation or board of directors’ recommendation change provisions described under “The Merger Agreement—Restrictions on Solicitations of Other Offers” and “The Merger Agreement—Recommendation and Recommendation Change” beginning on pages 62 and 64 in any material respect, without regard as to whether such breach results in an Acquisition Proposal;

our board of directors or any board committee withdraws its recommendation that our shareholders approve the principal terms of the Merger and adopt the Merger Agreement;

we fail to include our board of directors’ recommendation of the Merger Agreement in this proxy statement;

our board of directors or any board committee approves, or recommends that our shareholders approve, any Acquisition Proposal or Acquisition Transaction;

we enter into a letter of intent, memorandum of understanding or contract (other than a confidentiality agreement contemplated by the non-solicitation provisions of the Merger Agreement) accepting or agreeing to discuss or negotiate an Acquisition Proposal; or

following the date of any public announcement of a bona fide Acquisition Proposal, our board of directors fails to issue a press release to unconditionally reaffirm our board of directors’ recommendation within five business days after Parent or Merger Sub delivers a request in writing to do so (which request may be made only once with respect to an Acquisition Proposal).

by Supertex, if:

Parent or Merger Sub has breached any of its covenants or agreements in the Merger Agreement or if any of the representations and warranties of Parent and Merger Sub in the Merger Agreement were inaccurate when made or become inaccurate, and such breach or inaccuracy (i) would give rise to the failure of a condition to our obligation to consummate the Merger and (ii) if curable by Parent or Merger Sub through the exercise of commercially reasonable efforts, is not cured within 30 days or by July 14, 2014 after delivery of written notice to Parent of such breach or inaccuracy; or

prior to the Special Meeting, in order to enter into a definitive agreement with respect to a Superior Proposal, our board of directors effects a Recommendation Change and authorizes us to enter into an agreement for a transaction that constitutes a Superior Proposal, provided that immediately prior to such termination, we pay to Parent the termination fee as described under “The Merger Agreement—Termination Fees” beginning on page 66 and immediately following termination, we enter into a definitive agreement with respect to such Superior Proposal.

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Termination Fees (see page 66 ). If the Merger Agreement is terminated under certain circumstances, Supertex will be obligated to pay:

a termination fee of $15,760,000, and

the expenses of Parent incurred since January 1, 2014, up to $4.0 million.

The Special Meeting of Supertex Shareholders.

See “Questions and Answers About the Special Meeting and Merger” beginning on page 7 and “The Special Meeting” beginning on page 48.

Other Important Considerations.

Voting Agreement . In connection with the execution of the Merger Agreement, each of our directors, in his capacity as a shareholder of Supertex, has entered into a voting agreement with Parent, or the voting agreement, pursuant to which he or she has agreed to vote all of his or her shares of Supertex common stock in favor of the adoption of the Merger Agreement. See “The Voting Agreement” beginning on page 66.

Board Recommendation . Our board of directors recommends that Supertex shareholders vote “FOR” (1) the approval of the principal terms of the Merger and adoption of the Merger Agreement, or the Merger Proposal, (2) the approval, on an advisory (non-binding) basis, of certain compensation that may be paid or become payable to Supertex’s named executive officers that is based on or otherwise relates to the Merger, as well as the agreements pursuant to which such compensation may be paid or become payable, or the Advisory Compensation Proposal, and (3) the grant of authority to vote your shares to adjourn of the Special Meeting, if necessary, to solicit additional proxies, or the Adjournment Proposal. See “The Merger—Reasons for the Merger of Supertex and Recommendation of Our Board of Directors” beginning on page 20.

Reasons for the Merger . For a discussion of the material factors considered by our board of directors in reaching its conclusions and the reasons why our board of directors determined that the Merger is advisable and fair, see “The Merger—Reasons for the Merger of Supertex and Recommendation of Our Board of Directors” beginning on page 20.

Share Ownership of Directors and Executive Officers . See “Security Ownership of Certain Beneficial Owners and Management” beginning on page 69.

Interests of Supertex’s Directors and Executive Officers in the Merger . In considering the recommendation of our board of directors in favor of approval of the Merger Proposal, you should be aware that the Merger, certain provisions and conditions of the Merger Agreement and certain board actions taken prior to entry into the Merger Agreement will result in certain benefits to our directors and executive officers, including the continuation of certain indemnification and insurance arrangements and the acceleration of certain stock options. See “The Merger—Interests of Our Directors and Executive Officers in the Merger” beginning on page 32.

As of February 21, 2014, our directors and executive officers collectively beneficially held, including shares subject to options exercisable within 60 days of February 21, 2014, approximately 11.5% of the outstanding shares of Supertex common stock. See “Security Ownership of Certain Beneficial Owners and Management” beginning on page 69.

Opinion of Oppenheimer & Co., Inc. On February 9, 2014, Oppenheimer & Co., Inc., or Oppenheimer, rendered an oral opinion to the Supertex board of directors (which was confirmed in writing by delivery of Oppenheimer’s written opinion dated February 9, 2014), based upon and subject to the procedures followed, assumptions made, qualifications and limitations on the review undertaken and other matters considered by Oppenheimer in preparing its opinion, as to the fairness, from a financial point of view, of the Merger Consideration to be received by the holders of Supertex common stock, as of February 9, 2014. Oppenheimer’s opinion was based on the information available to Oppenheimer and the general economic, financial and stock market conditions and circumstances as they existed.

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Oppenheimer’s opinion was directed to the Supertex board of directors and only addressed the fairness, from a financial point of view, of the Merger Consideration to be received by the holders of Supertex common stock as of February 9, 2014 and does not address any other aspect or implication of the Merger as of any subsequent date. The full text of Oppenheimer’s written opinion is included as Annex C to this proxy statement and sets forth the procedures followed, assumptions made, qualifications and limitations on the review undertaken and other matters considered by Oppenheimer in preparing its opinion. We encourage our shareholders to carefully read the full text of Oppenheimer’s written opinion. However, neither Oppenheimer’s opinion nor the summary of its opinion and the related analyses set forth in this proxy statement are intended to be, and do not constitute, advice or a recommendation to our board of directors or any shareholder as to how to act or vote with respect to the Merger or related matters. See “The Merger—Opinion of the Financial Advisor to Supertex Board of Directors” beginning on page 25.

Regulatory Approvals (see page 47) . The Merger Agreement requires us, Parent and Merger Sub to use our and their reasonable best efforts to prepare any Merger notifications or obtain any government clearances or approvals required to close the Merger under the HSR Act and the rules promulgated thereunder by the Federal Trade Commission, or the FTC. After signing the Merger Agreement, we and Parent have concluded that we are required to file the notification under the HSR Act and have made such required filing.

Tax Consequences . Your receipt of cash in exchange for your shares of Supertex common stock in the Merger generally will cause you to recognize a gain or loss measured by the difference, if any, between the cash you receive in the Merger, determined before the deduction of any applicable withholding taxes, and your adjusted tax basis in your shares of Supertex common stock. If you are a U.S. person, as defined under “The Merger—Certain Material U.S. Federal Income Tax Consequences of the Merger to Supertex Shareholders,” such recognized gain will generally be subject to U.S. federal income taxation. If you are a non-U.S. person, also as defined under “The Merger—Certain Material U.S. Federal Income Tax Consequences of the Merger to Supertex Shareholders,” such recognized gain will generally not be subject to U.S. federal income taxation except in the circumstances described under “The Merger—Certain Material U.S. Federal Income Tax Consequences of the Merger to Supertex Shareholders.” Under U.S. federal income tax law, you will be subject to information reporting on cash received in the Merger unless an exemption applies. Backup withholding may also apply with respect to cash you receive in the Merger, unless you provide proof of an applicable exemption or a correct taxpayer identification number and otherwise comply with the applicable requirements of the backup withholding rules. You should consult your own tax advisor for a full understanding of how the Merger will affect your U.S. federal, state and local and/or foreign tax. See “The Merger—Certain Material U.S. Federal Income Tax Consequences of the Merger to Supertex Shareholders” beginning on page 44.

Dissenters’ Rights (see page 38) . If you do not wish to accept the $33.00 per share Merger Consideration, you may have the right to seek payment in cash of the fair market value of your shares, provided that you comply with certain procedures. These dissenters’ rights are subject to a number of restrictions and technical requirements. Generally, in order to exercise dissenters’ rights, among other things, (1) you must not vote to approve the Merger Proposal, (2) you must make a written demand for appraisal in compliance with California law and submit to Supertex the certificates representing your shares, which must be received by Supertex not later than 30 days after the date notice is provided that the Merger Agreement has been approved and (3) you must hold shares of Supertex common stock on the record date and continuously hold such shares through the consummation of the Merger. The fair market value of your shares of Supertex common stock as determined in accordance with California law may be more than, less than or the same as the Merger Consideration to be paid to non-dissenting shareholders. Merely voting against approval of the principal terms of the Merger and adoption of the Merger Agreement will not preserve your dissenters’ rights under California law. Annex D to this proxy statement contains a copy of the California statute relating to shareholders’ dissenters’ rights. Failure to follow all of the steps required by this statute may result in the loss of your dissenters’ rights.

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Market Price of Supertex Common Stock . Supertex common stock is listed on the NASDAQ Global Market under the ticker symbol “SUPX.” The $33.00 per share Merger Consideration represents a premium of approximately 35.4% to the $24.38 per share closing price of Supertex common stock on February 7, 2014, the last full trading day prior to the public announcement of the Merger.

QUESTIONS AND ANSWERS ABOUT THE SPECIAL MEETING AND MERGER

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Written notices of revocation and other communications with respect to revocation of any proxies should be addressed to: Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717.

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CAUTION REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement, and the documents to which we refer you in this proxy statement, include forward-looking statements that involve risks, uncertainties, estimates and assumptions. If such risks or uncertainties materialize or such estimates or assumptions prove incorrect, the results of Supertex and its consolidated subsidiaries could differ materially from those expressed or implied by such forward-looking statements and assumptions. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. In many cases you can identify forward-looking statements by the use of words such as “believe,” “estimate,” “anticipate,” “intend,” “plan,” “continue,” “predict,” “potential,” “contemplate,” “expect,” “may,” “will,” “likely,” “could,” “should” or “would” or other similar words or phrases, although the absence of such words or phrases does not necessarily mean that a statement is not forward-looking. These statements are subject to risks, uncertainties and other factors, including, among others:

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In addition, we are subject to risks and uncertainties and other factors detailed in Supertex’s annual report on Form 10-K for the fiscal year ended March 30, 2013, filed with the SEC on June 13, 2013, which should be read in conjunction with this proxy statement. For a detailed discussion of these and other risk factors, please refer to this and our other filings with the SEC on Forms 10-K, 10-Q and 8-K, which should be read in conjunction with this proxy statement. You can obtain copies of our Forms 10-K, 10-Q and 8-K and other filings for free at the Investors section of our website at www.supertex.com , at the SEC website at www.sec.gov or from commercial document retrieval services.

Many of the factors that will determine Supertex’s future results are beyond Supertex’s ability to control or predict. We cannot assure you that the actual results or developments reflected in these forward-looking statements will be realized or, even if they are realized, that they will have the expected effects on the Merger or on our business or operations. In light of the significant uncertainties inherent in the forward-looking statements contained herein, readers should not place undue reliance on forward-looking statements, which reflect management’s views only as of the date of this proxy statement. We cannot guarantee any future results, levels of activity, performance or achievements. The statements made in this proxy statement represent Supertex’s views as of the date of this proxy statement, and it should not be assumed that the statements made herein remain accurate as of any future date. Moreover, we assume no obligation and do not intend to update forward-looking statements or update the reasons for actual results differing materially from those anticipated in forward-looking statements, except as required by law.

THE PARTIES TO THE MERGER

Supertex, Inc.

Supertex is a California corporation with headquarters in Sunnyvale, California. Supertex designs, manufactures and markets a diversified range of integrated circuits, or ICs, utilizing high voltage analog and mixed signal technologies. Supertex’s principal executive offices are located at 1235 Bordeaux Drive, Sunnyvale, California 94089, and our telephone number is (408) 222-8888. For more information about Supertex, please visit our website at www.supertex.com . Our website address is provided as an inactive textual reference only. The information provided on our website is not part of this proxy statement, and therefore is not incorporated by reference. Supertex is publicly traded on the NASDAQ Global Market under the ticker symbol “SUPX.”

Microchip Technology Incorporated

Microchip Technology Incorporated is a Delaware corporation with headquarters in Chandler, Arizona. Microchip Technology Incorporated is a leading provider of microcontroller and analog ICs. The principal office address of Microchip Technology Incorporated is 2355 W. Chandler Blvd., Chandler, Arizona 85224, and its telephone number is (480) 792-7200. For more information about Microchip Technology Incorporated, please visit its website at www.microchip.com. This website address is provided as an inactive textual reference only. The information provided on Microchip Technology Incorporated’s website is not part of this proxy statement, and therefore is not incorporated by reference. Microchip Technology Incorporated is publicly traded on the NASDAQ Global Market under the ticker symbol “MCHP.”

Orchid Acquisition Corporation

Orchid Acquisition Corporation is a California corporation and is a wholly-owned subsidiary of Microchip Technology Incorporated and has not engaged in any business activity other than in connection with its formation and the Merger. The principal office address of Orchid Acquisition Corporation is 2355 W. Chandler Blvd., Chandler, Arizona 85224, and its telephone number is (480) 792-7200.

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THE MERGER

The discussion of the Merger and the Merger Agreement contained in this proxy statement summarizes the material terms of the Merger and the Merger Agreement. Although we believe that the description covers the material terms of the Merger and the Merger Agreement, this summary may not contain all of the information that is important to you. We urge you to read this proxy statement, the Merger Agreement, a copy of which is attached to this proxy statement as Annex A , and the other documents referred to herein (including the other annexes) carefully for a more complete understanding of the Merger and the Merger Agreement.

Background of the Merger

Over the past several years, Supertex’s business has faced increasingly strengthened competition in its end markets and it has become clear that in order to compete successfully in today’s global marketplace, size and scale are crucial. In part because the semiconductor market is characterized by substantial cyclicality and long lead times between the development of products and revenue-generating shipments, the Supertex board of directors periodically reviews Supertex’s business plan and potential strategic opportunities with Supertex management. These discussions focus, among other matters, on the competitive environment in the semiconductor industry and our specific target markets. The Supertex board of directors and Supertex management have also recognized that many of Supertex’s competitors are larger, more diversified companies, with substantially greater financial resources and capacity to invest in the development and marketing of new products and technologies. Accordingly, in connection with their desire to leverage Supertex’s technology and proprietary intellectual property, members of Supertex senior management and its board of directors have periodically reviewed and assessed its business strategy, the various trends and conditions affecting its business and the semiconductor industry generally, and a variety of strategic alternatives as part of its long-term strategy to increase revenue and profitability and maximize shareholder value. In light of these market and business dynamics, the Supertex board of directors and Supertex management have evaluated the strategic alternatives available to Supertex, including Supertex’s prospects as a standalone company.

The Supertex board of directors has continually looked for ways to increase shareholder value. Supertex management has held preliminary strategic discussions with companies that might be potential acquirers over the years, and has explored the potential of an acquisition when interest was expressed. In addition, Supertex looked for synergistic companies or product lines it could acquire, but did not find a business that it wanted to acquire on terms it deemed attractive. Supertex also deployed approximately $25 million of cash on stock repurchases and a one-time dividend in an attempt to increase shareholder value.

Despite being profitable and cash flow positive, Supertex has not been able to consistently materially grow its revenues and, in the past few years, the stock price has typically fluctuated between $18 and $25, with the stock price at the upper end of that range when the Merger was announced. The Supertex board of directors felt that Supertex’s value would increase with revenue growth and that, when the time was right, an acquisition of Supertex by a larger company would provide the size and scope beneficial for Supertex’s technology and products. As a result, Supertex’s business focus has been on new product development, design wins, and marketing and sales activity in order to grow its revenues.

Strategic Discussions with Companies other than Microchip in Prior Two Years

The Supertex board of directors, together with Supertex senior management, periodically reviews and considers Supertex’s long-term business strategy and the various strategic opportunities available, including whether the continued execution of Supertex’s strategy as a stand-alone company or the sale of Supertex to, or a combination of Supertex with, a third party offers the best avenue to maximize shareholder value. In connection with such review, members of Supertex senior management have met, from time to time, with various third parties who expressed an interest in engaging in a strategic transaction with Supertex.

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In 2012 and 2013, Supertex had discussions with five other strategic parties, not including Microchip, to explore areas of potential collaboration. During such meetings, Supertex management, accompanied by financial representatives, provided a presentation of Supertex’s business. During this period of time, Supertex management and financial representatives also conducted calls and other interactions with the various potential buyers to respond to initial diligence questions based on meetings with Supertex management. On August 12, 2012, Company A entered into non-disclosure agreement with Supertex so that Supertex and Company A could exchange confidential due diligence information and engage in discussions concerning a potential transaction in which Supertex would be acquired by Company A. The discussions did not result in the consummation of a transaction, as Company A never submitted a written proposal, and in part because Company A and Supertex appeared to be far apart on the value of Supertex.

Material Interactions with Microchip

Between November 2008 and December 2010, executives from Supertex and Microchip met on several occasions to explore areas of potential collaboration between the companies, during which Microchip expressed an interest in exchanging confidential due diligence information. These meetings were held pursuant to mutual non-disclosure agreements between Supertex and Microchip executed on November 12, 2008 and on November 11, 2010.

Between January and May 2008, Microchip acquired 597,400 shares, or 4.9% of Supertex common stock, in the open market. Microchip also sold certain put options in Supertex stock in the open market between June and September 2008, the contracts for which had put dates between March 2008 and March 2009. In December 2008 and March 2009, the exercise of multiple put contracts resulted in Microchip acquiring additional shares of Supertex stock, and by March 2009, Microchip owned 1,187,400 shares, or 9.2% of Supertex common stock. In May 2009, Microchip approached Supertex with an offer to acquire the remaining Supertex shares. However, this transaction was abandoned in June 2009 after a term sheet had been submitted with a proposed price of $28.73 per share, due diligence had begun, and drafts of a definitive agreement had been exchanged, although no exclusivity agreement had been executed. The Supertex board of directors met with Supertex management and Supertex’s then financial advisor regarding this proposed transaction. Beginning in July 2009, Microchip began selling its Supertex shares and had sold all of its Supertex shares by the end of September 2009.

In October 2010, Microchip again approached Supertex. On October 27, 2010, Supertex and Microchip entered into an exclusivity agreement and Microchip submitted a term sheet offering $29.00 per share, which was subsequently negotiated and increased to $30.00 per share on October 29, 2010, to acquire Supertex by merger. In addition, Supertex and Microchip entered into a new non-disclosure agreement on November 11, 2010. Drafts of a definitive agreement were exchanged and due diligence recommenced. Supertex management conferred with members of the Supertex board of directors regarding this proposed transaction. However, the discussions did not result in the consummation of a transaction and efforts were abandoned in December 2010. Thereafter, between March and May 2011, Microchip purchased a total of 248,059 shares of Supertex common stock in the open market, which it then sold between July and August 2013.

On December 9, 2013, Steve Sanghi, the Chairman of the Board, President and Chief Executive Officer of Microchip, called Henry Pao, the President and Chief Executive Officer of Supertex, to catch up on industry trends and Supertex’s business with the aim of seeing whether there could be a transaction between the two companies. On December 19, 2013, Mr. Sanghi and Dr. Pao had another conversation regarding the possibility of a strategic transaction, during which Mr. Sanghi communicated a price of $30.00 per share of Supertex common stock. Dr. Pao responded that he believed the value of Supertex to Microchip to be higher. On January 10, 2014, Mr. Sanghi and Dr. Pao spoke by telephone. During this conversation, Mr. Sanghi told Dr. Pao that he had calculated the value of Supertex to Microchip to be in the range of $30.00 to $31.00 per share of Supertex common stock. This range was consistent with the premium negotiated in 2009 and 2010. After consultation with Benedict Choy, a director and Senior Vice President of Supertex, Dr. Pao responded that he believed that the value of Supertex to Microchip should be $33.00 per share or higher. Mr. Sanghi indicated that he wished to invite Supertex management to visit Microchip and make a presentation about Supertex. Dr. Pao responded that he would do so only if Microchip would be willing to pay $33.00 per share for Supertex. Mr. Sanghi replied that he would have to consult with Microchip’s board of directors.

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Also, on January 10, 2014, in connection with the renewed discussions, Dr. Pao contacted Oppenheimer because of its qualifications, expertise, reputation and knowledge of Supertex’s business and affairs and the industry in which Supertex operates and because representatives from Oppenheimer, when at another firm, had previously discussed Supertex’s strategic positioning, future prospects, and strategic partners with the Supertex board of directors in connection with the Supertex board of director’s prior strategic discussions and review of business performance, risks, strategic direction and opportunities in prior years.

Over the weekend of January 11-12, 2014, Mr. Sanghi spoke with certain members of Microchip’s board of directors telephonically as well as with members of Microchip’s management team to discuss the potential transaction. Subsequently, on January 12, 2014, Mr. Sanghi confirmed to Dr. Pao that Microchip would offer a price of $33.00 per share, subject to confirmatory due diligence, which he proposed to begin immediately. Consequently, Mr. Sanghi provided a mutual non-disclosure agreement to Dr. Pao, which was executed on January 14, 2014. At Dr. Pao’s request, this agreement did not contain any exclusivity provision.

On January 13, 2014, Mr. Sanghi and Dr. Pao agreed that the Supertex team would visit the Microchip team in Chandler, Arizona on January 25, 2014 to make presentations concerning Supertex, to provide due diligence materials, and to continue discussions concerning the potential acquisition.

On January 14, 2014, Microchip sent a request for confidential due diligence information to Supertex, which included requests for a company overview and background and financial information.

Also, on January 14, 2014, Supertex entered into a letter agreement with Oppenheimer to engage Oppenheimer as its financial advisor.

On January 17, 2014, after Supertex’s audit committee meeting, Dr. Pao told Mark Loveless, a Supertex outside director and audit committee chair, about the discussions he had been having with Mr. Sanghi. Dr. Pao had been conferring with Mr. Choy throughout regarding his discussions with Mr. Sanghi.

Also, on January 17, 2014, representatives from Microchip and its outside legal counsel, Wilson Sonsini Goodrich & Rosati, P.C., or WSGR, sent a draft of the Merger Agreement to Oppenheimer. This draft was accompanied by a red-line to Supertex’s mark-up of the prior draft Merger Agreement, which Supertex’s outside legal counsel, Pillsbury Winthrop Shaw Pittman LLP, or Pillsbury, had provided to representatives from WSGR in 2010.

On January 22, 2014, Dr. Pao informed the other two outside directors of the discussions with Microchip by email.

On January 25, 2014, the management teams of both Supertex and Microchip met at Microchip’s headquarters in Chandler, Arizona to discuss and provide additional background regarding Supertex and to explore the possibility of a strategic transaction. In attendance at the meeting from Microchip were Mr. Sanghi as well as several key Microchip executives. In attendance at the meeting on behalf of Supertex were Dr. Pao, Mr. Choy and representatives from Oppenheimer. The parties discussed Supertex’s business, including its market position, growth drivers, organizational structure and end market opportunities. The parties also discussed Supertex’s product portfolio, manufacturing operations and financial performance. Executives from both Supertex and Microchip agreed that there were merits in pursuing a potential transaction and Mr. Sanghi and Dr. Pao confirmed their prior understanding regarding a price of $33.00 per share based on the due diligence provided in the interim.

Over the course of the next two weeks, several telephonic meetings occurred between representatives from Microchip and Supertex and their respective financial and legal advisors, as Microchip updated its due diligence conducted in the fall of 2010. During this time, Supertex and Microchip renewed their negotiations over the terms of the Merger Agreement, including provisions relating to Supertex’s business during the period after execution of the Merger Agreement, but prior to consummation of the Merger, the conditions to the closing of the transaction, the situations under which the parties could terminate the Merger Agreement and under which termination fees would be payable and the circumstances under which Supertex could

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review and accept alternative transactions. The parties also negotiated a proposed voting agreement to be entered into by members of the Supertex board of directors in their capacity as Supertex shareholders. In addition, during this time period, Supertex management prepared revenue forecasts and various assumptions regarding operating results for calendar years 2014 through 2018 for use in developing a discounted cash flow analysis.

On January 26, 2014, Dr. Pao sent an email to Supertex’s outside directors calling for a board meeting on January 30, 2014 to update them about the results of the meeting in Chandler, Arizona. On January 27, 2014, Mr. Sanghi spoke telephonically with members of Microchip’s board of directors to apprise them of the transaction and the diligence meeting.

On January 27, 2014, additional due diligence requests were made by Microchip concerning topics such as further financial and capitalization information and wafer fabrication operations. Supertex provided these additional items on an ongoing basis.

On January 28, 2014, representatives from Pillsbury and WSGR met telephonically to discuss the proposed transaction and review the draft of the Merger Agreement dated January 17, 2014, during which representatives from WSGR explained their proposed edits to the 2010 draft agreement from Pillsbury. As a result, representatives from Pillsbury communicated to Supertex and Oppenheimer a variety of issues which Supertex might wish to raise in the next revision of the Merger Agreement.

Also, on January 30, 2014, Supertex received additional due diligence requests from Microchip concerning its manufacturing facilities, which Supertex provided later that day. Additionally, Microchip requested tax due diligence, which Supertex and representatives from Oppenheimer provided to Microchip.

On January 30, 2014, representatives from Pillsbury sent an initial draft of Supertex’s disclosure schedules as related to the draft of the Merger Agreement dated January 17, 2014 to representatives from WSGR and Microchip. Additionally, representatives from WSGR provided representatives from Pillsbury a draft of the voting agreement. This draft of the voting agreement was accompanied by a red-line to Supertex’s mark-up of the prior draft voting agreement representatives from Pillsbury had provided to representatives from WSGR in 2010.

Later, on January 30, 2014, the Supertex board of directors met telephonically, with representatives from Pillsbury and Oppenheimer participating, to discuss the valuation proposed by Microchip and to consider a potential strategic transaction with Microchip. At this meeting, a representative of Pillsbury reviewed with the members of the Supertex board of directors the directors’ fiduciary duties and Supertex management sought the Supertex board of directors’ guidance as to key legal and business issues to further negotiate in connection with the draft Merger Agreement. In responding and choosing such provisions, the Supertex board of directors emphasized the need for assurances that the transaction would close, the need to maintain stability among Supertex’s employees both between signing and closing and to ensure that the proposed Merger Agreement did not unduly restrict the Supertex board of directors’ ability to take actions necessary to comply with its fiduciary duties during the period following entry into the Merger Agreement. The Supertex board of directors also highlighted the importance of having appropriate termination rights and remedies available to Supertex under the Merger Agreement. Oppenheimer provided a preliminary financial analysis relating to a potential acquisition of Supertex by Microchip. The Supertex board of directors also reviewed Supertex’s one-year, two-year, four-year and ten-year stock price averages of $22.87 per share, $20.88 per share, $21.78 per share and $25.34 per share, respectively. In addition, the Supertex board of directors was advised that 99% of the stock traded below $27.00 per share over the last two years.

From January 30, 2014 through February 7, 2014, representatives from Microchip, Supertex and their respective financial and legal advisors further discussed and negotiated the outstanding issues with respect to the terms of Microchip’s proposed acquisition of Supertex, including with respect to mechanics and timing of the potential merger. The management teams and legal and financial advisors of Microchip and Supertex further negotiated the terms and conditions of the Merger Agreement, including, among other things, the termination provisions, Microchip’s right to terminate the Merger Agreement in the event of a material adverse effect, the termination fee and transaction expenses provisions, the non-solicitation covenants, the Supertex board of directors’ ability to change its recommendation of the Merger and other representations, warranties and covenants. During that period, drafts of the Merger Agreement were exchanged and negotiated between the parties and Supertex’s and Microchip’s respective legal advisors participated in numerous conference calls.

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On January 31, 2014, Microchip held a tax due diligence call with advisors from both companies. Microchip’s representatives were in attendance as well as a representative from KPMG LLP. Representatives from Supertex and Oppenheimer were in attendance on behalf of Supertex.

Also, on January 31, 2014, representatives from Pillsbury provided a revised draft of the Merger Agreement to representatives from WSGR and Microchip, which was a revision of the draft Merger Agreement dated January 17, 2014 and addressed certain terms including deal certainty provisions as well as deal protection provisions such as the termination fee, non-solicitation provisions, and termination rights.

On February 1, 2014, after further review with Supertex, representatives from Pillsbury sent a revised version of Supertex’s disclosure schedules to representatives from WSGR and Microchip for review.

On February 3, 2014, representatives from Pillsbury and WSGR met telephonically to discuss WSGR’s comments to the revised Merger Agreement dated February 1, 2014. Subsequently, on February 4, 2014, representatives from Pillsbury provided written feedback on several open items to representatives from WSGR as a result of the discussion the day prior, which included a proposal covering the major open items, including deal protection terms such as the termination fee and termination rights.

Later, on February 4, 2014, Microchip requested additional financial due diligence from Supertex.

On February 5, 2014, Microchip requested additional due diligence items around the product portfolio from Supertex, after which Dr. Pao provided feedback concerning any current and new product introductions. Additionally, later that day, Microchip held a board meeting to discuss the proposed transaction with Supertex, review of the results of the due diligence, synergy and valuation analysis, and as a result decided to move forward with the transaction. Mr. Sanghi called Dr. Pao and a representative of Oppenheimer on separate occasions to discuss some of the key issues outstanding on the Merger Agreement contained in Pillsbury’s proposal. Also, representatives from WSGR provided representatives from Pillsbury with some questions and comments regarding the disclosure schedule.

On February 6, 2014, representatives from WSGR provided representatives from Pillsbury with a revised draft of the Merger Agreement which reflected their discussions earlier during the week and Microchip’s reaction to Pillsbury’s proposal. Subsequently, on February 6, 2014, representatives from Pillsbury and WSGR met telephonically to discuss the revisions to the Merger Agreement and to resolve Pillsbury’s remaining comments on both the voting agreement and Merger Agreement.

Representatives from WSGR sent copies of a revised Merger Agreement and voting agreement to representatives from Pillsbury on February 7, 2014, in which they had resolved the remaining open items and finalized the agreements. Also, on February 7, 2014, representatives from Pillsbury provided an updated draft of Supertex’s disclosure schedule to representatives from WSGR.

On February 7, 2014, the Supertex board of directors met telephonically, with representatives from Pillsbury and Oppenheimer also participating. Representatives from Oppenheimer presented Oppenheimer’s financial analysis of the consideration to be received by holders of Supertex common stock pursuant to the Merger Agreement and responded to questions. Representatives from Pillsbury again reviewed the Supertex board of directors’ fiduciary duties in the context of a merger and reviewed the draft Merger Agreement circulated previously to the Supertex board of directors, including the resolution of the issues highlighted to the Supertex board of directors at its January 30, 2014, meeting. The Supertex board of directors discussed the reasons for the Merger and the alternatives, including remaining a stand-alone company, trying to negotiate a higher price from Microchip, or terminating discussions with Microchip and seeking a higher price elsewhere. The Supertex board of directors then discussed the prospects and risks of remaining a stand-alone company and for a variety of reasons determined that the present time was an optimal time to sell Supertex. The Supertex board of directors also ratified Supertex entering into the January 14, 2014, letter agreement with Oppenheimer.

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On February 8 and 9, 2014, representatives from Pillsbury and WSGR, together with representatives from Supertex and Microchip, worked together to resolve Microchip’s comments to the disclosure schedule and finalize it in the morning of February 9, 2014.

In the afternoon of February 9, 2014, Microchip’s board of directors met telephonically to review the final terms of the final Merger Agreement and to consider and approve the transaction.

In the afternoon of February 9, 2014, the Supertex board of directors then met telephonically, with representatives from Pillsbury and Oppenheimer also participating. Representatives from Oppenheimer responded to questions from the Supertex board of directors regarding its financial analysis presented at the February 7, 2014 board meeting and orally rendered Oppenheimer’s opinion, which was confirmed by delivery of written opinion dated February 9, 2014, to the effect that as of February 9, 2014 and based on and subject to the considerations, limitations, and other matters set forth therein, the Merger Consideration to be received by the holders of shares of Supertex common stock pursuant to the Merger Agreement was fair to such holders from a financial point of view. Representatives from Pillsbury next reviewed the Supertex board of directors’ discussion from the prior meeting concerning the reasons for the Merger and the alternatives and the minor changes to the voting agreement and Merger Agreement from the versions sent to the Supertex board of directors in advance of the prior meeting and responded to questions. After further discussion, the Supertex board of directors, having determined that the terms of the Merger Agreement and the transactions contemplated thereby on the terms discussed by the board of directors at the meeting, including the Merger, were fair to and in the best interests of the Supertex shareholders, unanimously approved and declared advisable the Merger Agreement and the transactions contemplated thereby, including the Merger, directed that the Merger Agreement as approved by the board of directors be submitted to the Supertex shareholders for adoption and approval, and recommended that the Supertex shareholders vote in favor of the adoption and approval for the Merger Agreement and the transactions contemplated thereby, including the Merger.

Later, on February 9, 2014, the Merger Agreement was entered into by Microchip and Supertex and voting agreements were entered into by Microchip and each of the members of the Supertex board of directors, in their capacities as Supertex shareholders. Microchip and Supertex issued a joint press release announcing the execution of the Merger Agreement before the opening of trading in Microchip and Supertex common stock on February 10, 2014.

On February 18, 2014, each of Supertex and Microchip filed a notification and report form with the FTC and the DOJ under the HSR Act and each requested early termination of the waiting period.

Reasons for the Merger of Supertex and Recommendation of our Board of Directors

Reasons for the Recommendation of our Board of Directors

After careful review and consideration of the terms and conditions of the Merger, as set forth in the Merger Agreement, the Supertex board of directors determined that the Merger and the Merger Agreement, and the transactions contemplated thereby, are fair to, and in the best interests of, Supertex and its shareholders and declared the Merger Agreement and the transactions contemplated thereby, including the Merger, to be advisable to Supertex and its shareholders. Accordingly, the Supertex board of directors unanimously approved the Merger and the Merger Agreement and unanimously recommends that Supertex shareholders vote “ FOR ” adoption and approval of the Merger Proposal.

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In the course of determining that the Merger, the Merger Agreement and the transactions contemplated thereby are fair to, in the best interests of and advisable to Supertex and its shareholders, the Supertex board of directors consulted with management as well as its financial and legal advisors and considered a number of factors in making its determination, including the following substantive factors and potential benefits of the Merger, each of which the Supertex board of directors believed supported its decision (which are not listed in any relative order of importance):

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The Supertex board of directors also considered a variety of potentially negative factors in its deliberations concerning the Merger Agreement and the Merger, including the following (not in any relative order of importance):

The foregoing discussion of the information and factors considered by the Supertex board of directors is not intended to be exhaustive but includes the material factors considered by the Supertex board of directors. In view of the wide variety of factors considered in connection with its evaluation of the Merger and the complexity of these matters, the Supertex board of directors did not find it useful to and did not attempt to quantify, rank, or otherwise assign relative weights to these factors. In addition, the Supertex board of directors did not undertake to make any specific determination as to whether any particular factor, or any aspect of any particular factor, was favorable or unfavorable to its ultimate determination, but rather the Supertex board of directors conducted an overall analysis of the factors described above, including discussions with Supertex management and its financial and legal advisors. In considering the factors described above, individual members of the Supertex board of directors may have given different weights to different factors.

Our board of directors recommends that you vote “FOR” the approval of the Merger Proposal.

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Opinion of the Financial Advisor to Supertex Board of Directors

Supertex engaged Oppenheimer as its financial advisor in connection with the Merger. In connection with this engagement, the Supertex board of directors requested that Oppenheimer evaluate the fairness, from a financial point of view, of the Merger Consideration to be received in the Merger, taken together, by holders of Shares. On February 9, 2014, at a meeting of the Supertex board of directors held to evaluate the Merger, Oppenheimer rendered to the Supertex board of directors an oral opinion, confirmed by delivery of a written opinion dated February 9, 2014, or the Opinion, to the effect that, as of that date and based on and subject to the matters described in the Opinion, the $33.00 per share cash consideration to be received in the Merger by holders of Shares was fair, from a financial point of view, to such holders.

The full text of Oppenheimer’s written Opinion, which describes the assumptions made, procedures followed, matters considered and limitations on the review undertaken, is attached to this document as  Annex C and is incorporated by reference in its entirety. Oppenheimer’s opinion was provided for the use of the Supertex board of directors (in its capacity as such) in connection with its evaluation of the Merger Consideration from a financial point of view and did not address any other terms, aspects or implications the Merger, including, without limitation, the form or structure of the Merger or any term, aspect or implication of any other agreement, arrangement or understanding entered into in connection with the Merger or otherwise. Oppenheimer expressed no view as to, and its Opinion did not address, the underlying business decision of Supertex to proceed with or effect the Merger or the relative merits of the Merger as compared to any alternative business strategies that might exist for Supertex or the effect of any other transaction in which Supertex might engage. Oppenheimer’s Opinion should not be construed as creating any fiduciary duty on the part of Oppenheimer to any party and the Opinion does not constitute a recommendation to any shareholder as to how such shareholder should vote or act with respect to any matters relating to the Merger or otherwise. This summary of Oppenheimer’s Opinion is qualified in its entirety by reference to the full text of its Opinion.

In arriving at its Opinion, Oppenheimer:

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In rendering its Opinion, Oppenheimer relied upon and assumed, without independent verification or investigation, the accuracy and completeness of all of the financial and other information provided to or discussed with Oppenheimer by Supertex and its employees, representatives and affiliates or otherwise reviewed by Oppenheimer. With respect to the financial forecasts and estimates relating to Supertex referred to above, Oppenheimer assumed, at the direction of Supertex management and with Supertex’s consent, without independent verification or investigation, that such forecasts and estimates were reasonably prepared on bases reflecting the best available information, estimates and judgments of the management of Supertex as to the future financial condition and operating results of Supertex and the other matters covered thereby. At the direction of representatives from Supertex, Oppenheimer also assumed that the final terms of the Merger Agreement did not vary materially from those set forth in the draft reviewed by Oppenheimer. Oppenheimer also assumed, with the consent of Supertex, that the Merger will be consummated in accordance with its terms without waiver, modification or amendment of any material term, condition or agreement and in compliance with all applicable laws and other requirements and that, in the course of obtaining the necessary regulatory or third party approvals, consents and releases with respect to the Merger, no delay, limitation, restriction or condition will be imposed that would have an adverse effect on Supertex or the Merger. Oppenheimer neither made nor obtained any independent evaluations or appraisals of the assets or liabilities, contingent or otherwise, of Supertex.

Oppenheimer expressed no view as to, and its Opinion did not address the underlying valuation, future performance or long term viability of Supertex or the price at which Supertex common stock will trade at any time. Oppenheimer expressed no view as to, and its Opinion did not address, any terms or other aspects or implications of the Merger (other than the Merger Consideration to the extent expressly specified therein) or any aspect or implication of any other agreement, arrangement or understanding entered into in connection with the Merger or otherwise, including, without limitation, the fairness of the amount or nature of the compensation resulting from the Merger to any individual officers, directors or employees of Supertex, or class of such persons, relative to the Merger Consideration. In addition, Oppenheimer expressed no view as to, and its Opinion did not address, the underlying business decision of Supertex to proceed with or effect the Merger nor did Oppenheimer’s Opinion address the relative merits of the Merger as compared to any alternative business strategies that might exist for Supertex or the effect of any other transaction in which Supertex might engage. Oppenheimer’s Opinion was necessarily based on the information available to it and general economic, financial and stock market conditions and circumstances as they existed and could be evaluated by Oppenheimer on the date of its Opinion. It should be understood that, although subsequent developments may affect Oppenheimer’s Opinion, Oppenheimer does not have any obligation to update, revise or reaffirm its Opinion.

Oppenheimer is not a legal, tax, regulatory or accounting advisor and has relied on the assessments made by Supertex and its advisors with respect to such issues. This Opinion does not address any legal, tax, regulatory or accounting matters. In addition, Oppenheimer’s Opinion does not constitute a solvency opinion or a fair value opinion, and Oppenheimer has not evaluated the solvency or fair value of Supertex under any federal or state laws relating to bankruptcy, insolvency or similar matters. Except as described in this summary, Supertex imposed no other instructions or limitations on Oppenheimer with respect to the investigations made or the procedures followed by it in rendering its Opinion.

This summary is not a complete description of Oppenheimer’s Opinion or the financial analyses performed and factors considered by Oppenheimer in connection with its Opinion. The preparation of a financial opinion is a complex analytical process involving various determinations as to the most appropriate and relevant methods of financial analysis and the application of those methods to the particular circumstances and, therefore, a financial opinion is not readily susceptible to summary description. Oppenheimer arrived at its ultimate opinion based on the results of all analyses undertaken by it and assessed as a whole, and did not draw, in isolation, conclusions from or with regard to any one factor or method of analysis for purposes of its Opinion. Accordingly, Oppenheimer believes that its analyses and this summary must be considered as a whole and that selecting portions of its analyses and factors or focusing on information presented in tabular format, without considering all analyses and factors or the narrative description of the analyses, could create a misleading or incomplete view of the processes underlying Oppenheimer’s analyses and Opinion.

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In performing its analyses, Oppenheimer considered industry performance, general business, economic, market and financial conditions and other matters existing as of the date of its Opinion, many of which are beyond Supertex’s control. No company, business or transaction used in the analyses is identical to Supertex or the Merger, and an evaluation of the results of those analyses is not entirely mathematical. Rather, the analyses involve complex considerations and judgments concerning financial and operating characteristics and other factors that could affect the acquisition, public trading or other values of the companies, business segments or transactions analyzed.

The assumptions and estimates contained in Oppenheimer’s analyses and the ranges of valuations resulting from any particular analysis are not necessarily indicative of actual values or future results, which may be significantly more or less favorable than those suggested by its analyses. In addition, analyses relating to the value of businesses or securities do not purport to be appraisals or to reflect the prices at which businesses or securities actually may be sold or acquired. Accordingly, the assumptions and estimates used in, and the results derived from, Oppenheimer’s analyses are inherently subject to substantial uncertainty.

Oppenheimer was not requested to, and it did not, recommend the specific consideration payable in the Merger. The type and amount of consideration payable in the Merger was determined through negotiation between Supertex and Microchip and was approved by the Supertex board of directors. The decision to enter into the Merger Agreement was solely that of the Supertex board of directors. Oppenheimer’s opinion and financial analysis were only one of many factors considered by the Supertex board of directors in its evaluation of the Merger and should not be viewed as determinative of the views of the Supertex board of directors or management with respect to the Merger or the consideration payable in the Merger.

The following is a summary of the material financial analyses reviewed with the Supertex board of directors in connection with the Opinion dated February 9, 2014.  The financial analyses summarized below include information presented in tabular format. In order to fully understand Oppenheimer’s financial analyses, the tables must be read together with the text of each summary. The tables alone do not constitute a complete description of the financial analyses. Considering the data in the tables below without considering the full narrative description of the financial analyses, including the methodologies and assumptions underlying the analyses, could create a misleading or incomplete view of Oppenheimer’s financial analyses. 

Selected Companies Analysis .  Oppenheimer reviewed publicly available financial information of the following twenty-two selected publicly traded companies, which are providers of semiconductors and analog and mixed signal integrated circuits:

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Oppenheimer reviewed (a) enterprise values of the selected companies, calculated as fully-diluted equity values based on closing stock prices on February 5, 2014 plus debt less cash and cash equivalents, as multiples of calendar years 2013 and 2014 (i) estimated revenue and (ii) estimated earnings before interest, taxes, depreciation and amortization as adjusted for non-cash compensation expense and one-time, non-recurring items, referred to as Adjusted EBITDA, and (b) equity values for the selected companies, as multiples of calendar years 2013 and 2014 estimated earnings per share, or EPS. Financial data of the selected companies were based on publicly available research analysts’ estimates, public filings and other publicly available information. The overall low to high ranges of calendar year 2013 and calendar year 2014 estimated revenue multiples observed for the selected companies were 0.7x to 4.6x (with a mean of 2.5x) and 0.7x to 4.1x (with a mean of 2.3x), respectively. The overall low to high ranges of calendar year 2013 and calendar year 2014 estimated Adjusted EBITDA multiples observed for the selected companies were 3.8x to 18.1x (with a mean of 10.6x) and 5.6x to 14.1x (with a mean of 8.9x), respectively. The overall low to high ranges of calendar year 2013 and calendar year 2014 EPS multiples observed for the selected companies were 6.1x and 30.0x (with a mean of 20.0x) and 10.1x and 25.0x (with a mean of 16.8x), respectively. Oppenheimer then applied the low to high selected ranges of calendar year 2013 and calendar year 2014 estimated (i) revenue multiples of 2.1x to 2.9x and 2.0x to 2.7x, respectively, and (ii) Adjusted EBITDA multiples of 9.0x to 12.2x and 7.6x to 10.3x, respectively, derived from the selected companies to corresponding data of Supertex. Financial data of Supertex were based on Supertex’s public filings, internal estimates of Supertex management, and calculations based on such estimates. This analysis resulted in low to high enterprise value ranges for Supertex of (i) $141.4 million to $191.4 million and $144.0 million to $194.8 million, based on the selected calendar year 2013 and calendar year 2014 revenue multiples, respectively, and (ii) $111.3 million to $150.5 million and $103.9 million to $140.6 million, based on calendar year 2013 and calendar year 2014 Adjusted EBITDA multiples, respectively. Oppenheimer then calculated implied per share equity values based on (i) debt of $0.0 million and cash of $158.8 million, in each case, as of December 28, 2013 and (ii) shares outstanding using the treasury stock method, and based on applying EPS selected multiples of 17.0x to 23.0x and 14.3x to 19.4x calendar year 2013 and calendar year 2014 earnings of Supertex, respectively, as derived from the selected companies analysis. These calculations yielded the following per share equity value ranges:

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From these calculations Oppenheimer selected the following implied per Share equity reference ranges for Supertex, as compared to the Merger Consideration:

Selected Precedent Transactions Analysis.  Oppenheimer reviewed, to the extent publicly available, financial information relating to the following twenty-two selected transactions, which transactions involve companies that are providers of semiconductors and analog and mixed signal integrated circuits:

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Oppenheimer reviewed enterprise values, calculated as the purchase prices paid for the target companies in the selected transactions plus debt less cash and cash equivalents, (i) as multiples of such target companies’ latest 12 months for which financial information was available at the time of announcement, or LTM, revenue and LTM Adjusted EBITDA and (ii) as multiples of such target companies’ next twelve months immediately following LTM, or NTM, revenue and NTM Adjusted EBITDA. Financial data of the selected transactions were based on research analysts’ estimates, public filings and other information publicly available (at the announcement of the applicable transaction). The overall low to high range of LTM revenue multiples observed for the selected transactions was 0.6x to 3.6x (with a mean of 1.6x) and the overall low to high range of LTM Adjusted EBITDA multiples observed for the selected transactions was 6.1x to 19.4x (with a mean of 12.5x). The overall low to high range of NTM revenue multiples observed for the selected transactions was 0.4x to 3.2x (with a mean of 1.5x) and the overall low to high range of NTM Adjusted EBITDA multiples observed for the selected transactions was 5.3x to 15.7x (with a mean of 9.7x). Oppenheimer then applied (i) a selected low to high range of LTM revenue and LTM Adjusted EBITDA multiples of 1.4x to 1.9x and 10.6x to 14.4x, respectively, derived from the selected transactions to the LTM revenue (as of December 28, 2013) and LTM Adjusted EBITDA of Supertex and (ii) a selected low to high range of NTM revenue and NTM Adjusted EBITDA multiples of 1.3x to 1.8x and 8.2x to 11.2x, respectively, derived from the selected transactions to the NTM revenue (as of December 28, 2013) and NTM Adjusted EBITDA of Supertex. Financial data of Supertex were based on Supertex’s public filings, internal estimates of Supertex management, and calculations based on such estimates. This analysis resulted in low to high enterprise value ranges for Supertex of (i) $92.3 million to $124.8 million and $131.0 million to $177.3 million, based on the selected LTM revenue and LTM Adjusted EBITDA multiples, respectively, and (ii) $95.6 million to $129.4 million and $112.7 million to $152.4 million, based on the selected NTM revenue and NTM Adjusted EBITDA multiples, respectively. Oppenheimer then calculated implied per share equity values based on (i) debt of $0.0 million and cash of $158.8 million, in each case, as of December 28, 2013 and (ii) shares outstanding using the treasury stock method:

From these calculations Oppenheimer selected the following implied per Share equity reference ranges for Supertex, as compared to the Merger Consideration:

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Discounted Cash Flow Analysis .  Oppenheimer conducted an illustrative discounted cash flow analysis, which is designed to imply a potential value of Supertex by calculating the estimated present value of the standalone after-tax free cash flows that Supertex was forecasted to generate during the calendar year ending December 28, 2014 through the full calendar year ending December 28, 2018 (refer to section entitled “Selected Unaudited Prospective Financial Information” beginning on page 40). For purposes of this analysis, stock-based compensation was treated as a cash expense. Oppenheimer calculated terminal values for Supertex by applying to Supertex’s estimated calendar year 2018 adjusted EBITDA a selected range of terminal value adjusted EBITDA multiples of 12.0x to 14.0x. The cash flows and terminal values were then discounted to present value using discount rates ranging from 13.2% to 17.2%, which were based on an estimated weighted average cost of capital. This analysis indicated the following approximate implied per share equity reference range for Supertex common stock, as compared to the Merger Consideration:

Other Factors.  Oppenheimer also noted certain additional factors that were not considered part of Oppenheimer’s financial analyses with respect to its opinion but were referenced for informational purposes, including, among other things, the following:

Miscellaneous

In the ordinary course of business, Oppenheimer and its affiliates may actively trade securities of Supertex, securities of Microchip and their respective affiliates for Oppenheimer’s and its affiliates’ own accounts and for the accounts of customers and, accordingly, may at any time hold a long or short position in such securities.

Supertex selected Oppenheimer to act as its financial advisor in connection with the Merger based on Oppenheimer’s reputation and experience. Oppenheimer is an internationally recognized investment banking firm and, as a part of its investment banking business, is regularly engaged in valuations of businesses and securities in connection with acquisitions and mergers, underwritings, secondary distributions of securities, private placements and valuations for other purposes. The issuance of Oppenheimer’s opinion was approved by an authorized committee of Oppenheimer.

Supertex has entered into a written agreement with Oppenheimer which provides for Supertex to pay Oppenheimer for its financial advisory services in connection with the Merger an aggregate fee currently estimated to be approximately $3.95 million, $250,000 of which was payable in connection with Oppenheimer’s delivery of its Opinion and approximately $3.70 million of which is contingent upon consummation of the Merger. During the two-year period prior to the date of Oppenheimer’s Opinion, no material investment banking, financial services or other commercial services were provided by Oppenheimer or any of their affiliates to Supertex or Microchip for which Oppenheimer received fees.

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Neither Supertex nor any person acting on its behalf has employed, retained or compensated any person to make solicitations or recommendations to security holders of Supertex with respect to the Merger.

Delisting and Deregistration of Supertex Common Stock

If the Merger is consummated, Supertex common stock will be delisted from the NASDAQ Global Market and deregistered under the Exchange Act. Therefore, the provisions of the Exchange Act will no longer apply to Supertex, including the requirement that Supertex furnish a proxy or information statement to Supertex shareholders in connection with meetings of Supertex shareholders. Supertex will also no longer be required to file periodic reports with the SEC.

Accounting

For financial reporting purposes, the Merger will be accounted for by Parent under a purchase price allocation where the assets and liabilities will be presented at their fair value.

Effects on Supertex if the Merger is Not Consummated

If Supertex shareholders do not approve the Merger Proposal, or if the Merger is not consummated for any other reason, shareholders will not receive any payment for their shares in connection with the Merger. Instead, Supertex will remain an independent public company and the Supertex common stock will continue to be listed and traded on the NASDAQ Global Market. In addition, if the Merger is not consummated, we expect that management will operate the business in a manner similar to that in which it is being operated today and that Supertex shareholders will continue to be subject to the same risks and opportunities as they currently are, including, among other things, the nature of the semiconductor component industry on which Supertex’s business largely depends, and general industry, economic, regulatory and market conditions. Accordingly, if the Merger is not consummated, there can be no assurance as to the effect of these risks and opportunities on the future value of your Supertex shares. In such event, from time to time, we expect that the Supertex board of directors will evaluate and review, among other things, the business operations, properties, dividend policy and capitalization of Supertex and make such changes as are deemed appropriate and continue to seek to identify strategic alternatives to enhance shareholder value. If Supertex shareholders do not approve the Merger Proposal, or if the Merger is not consummated for any other reason, there can be no assurance that any other transaction acceptable to Supertex will be offered, or that the business, prospects or results of operations of Supertex will not be adversely impacted. We may be required to pay the Parent’s expenses and the termination fees as described in “The Merger Agreement—Termination Fees.”

Interests of Our Directors and Executive Officers in the Merger

In considering the recommendation of the Supertex board of directors with respect to the Merger, you should be aware that some of the Supertex directors and executive officers have interests in the Merger that are different from, or in addition to, the interests of our shareholders generally. These interests may present them with actual or potential conflicts of interest, and these interests, to the extent material, are described below. The Supertex board of directors was aware of these interests and considered them, among other matters, in approving the Merger Agreement and the Merger.

Treatment of Stock Options

As of the record date, there were 577,900 shares of Supertex common stock subject to stock options granted under our equity incentive plans to our current ten executive officers and directors.

Upon the consummation of the Merger, all outstanding vested options to acquire Supertex common stock pursuant to our 2001 Stock Option Plan and our 2009 Equity Incentive Plan held by our executive officers and employee directors, like all other outstanding and vested stock options held by our other employees, will be cancelled, and in consideration for the cancellation of vested options, the holder of any such option will receive an amount equal to the number of shares of our common stock underlying the option multiplied by the amount (if any) by which $33.00 exceeds the exercise price for each share of Supertex common stock underlying the options, without interest and less any applicable withholding taxes. If the exercise price of the vested option is equal to or exceeds $33.00, the holder of such option will not be entitled

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to any Merger Consideration. Pursuant to our 2009 Equity Incentive Plan, all outstanding options to acquire our common stock held by our non-employee directors will accelerate and vest in full on a change of control, which includes the Merger, and will likewise be cancelled in exchange for the consideration described above.

All outstanding unvested options held by our executive officers and employee directors, like all other outstanding unvested options held by our other employees will be assumed by Parent and remain subject to substantially the same terms and conditions, except that: (1) the number of shares of Parent common stock subject to each such outstanding unvested option will be equal to the product of the number of shares of our common stock underlying such option and the Exchange Ratio, rounded down to the nearest whole share, and (2) the exercise price of each such outstanding unvested option will be equal to the quotient determined by dividing the exercise price by the Exchange Ratio, rounded up to the nearest cent.

Our seven executive officers as a group will receive $2,758,050 pursuant to the Merger Agreement in connection with the cancellation of their 227,000 vested options with exercise prices less than $33.00 per share upon the consummation of the Merger, of which Henry C. Pao, our President, CEO and director, and Benedict C.K. Choy, our Senior Vice President and director, will each receive $607,500 in connection with 50,000 vested options each holds. A total of 78,000 vested options held by our seven executive officers as a group will be cancelled for no consideration since the options have an exercise price in excess of $33.00, of which 15,000 are held by each of Mr. Pao and Mr. Choy. Our seven executive officers as a group will hold 128,900 unvested options, which will be assumed by Microchip pursuant to the Merger Agreement, of which 20,000 are held by each of Mr. Pao and Mr. Choy.