NOTE

Exhibit 4.3

NOTE

UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY TO LEXAR MEDIA, INC. (THE “COMPANY”) OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY (AND ANY PAYMENT HEREON IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN. THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY IS EXCHANGEABLE FOR SECURITIES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE DEPOSITARY OR ITS NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE AND, UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR SECURITIES IN DEFINITIVE FORM, THIS SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITARY.

THIS SECURITY AND THE SHARES OF COMMON STOCK ISSUABLE UPON CONVERSION OF THIS SECURITY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR ANY STATE SECURITIES LAWS. NEITHER THIS SECURITY, THE SHARES OF COMMON STOCK ISSUABLE UPON CONVERSION OF THIS SECURITY NOR ANY INTEREST OR PARTICIPATION HEREIN OR THEREIN MAY BE REOFFERED, SOLD, ASSIGNED, TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE ABSENCE OF SUCH REGISTRATION OR UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT SUBJECT TO, REGISTRATION. EACH PURCHASER OF THIS SECURITY IS HEREBY NOTIFIED THAT THE SELLER OF THIS SECURITY MAY BE RELYING ON THE EXEMPTION FROM THE PROVISIONS OF SECTION 5 OF THE SECURITIES ACT PROVIDED BY RULE 144A THEREUNDER.

THE HOLDER OF THIS SECURITY, BY ITS ACCEPTANCE HEREOF, AGREES TO OFFER, SELL OR OTHERWISE TRANSFER SUCH SECURITY, PRIOR TO THE DATE (THE “RESALE RESTRICTION TERMINATION DATE”) WHICH IS TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUE DATE HEREOF AND THE LAST DATE ON WHICH LEXAR MEDIA, INC. OR ANY AFFILIATE OF LEXAR MEDIA, INC. WAS THE OWNER OF

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THIS SECURITY (OR ANY PREDECESSOR OF SUCH SECURITY) ONLY (A) TO LEXAR MEDIA, INC. OR ANY PARENT OR SUBSIDIARY THEREOF, (B) FOR SO LONG AS THE SECURITIES ARE ELIGIBLE FOR RESALE PURSUANT TO RULE 144A, TO A PERSON IT REASONABLY BELIEVES IS A “QUALIFIED INSTITUTIONAL BUYER” AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT THAT PURCHASES FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHICH NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN RELIANCE ON RULE 144A, (C) PURSUANT TO A REGISTRATION STATEMENT WHICH HAS BEEN DECLARED EFFECTIVE UNDER THE SECURITIES ACT, OR (D) PURSUANT TO ANOTHER AVAILABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT, SUBJECT TO LEXAR MEDIA, INC.’S AND THE TRUSTEE’S RIGHT PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER PURSUANT TO CLAUSE (D) TO REQUIRE THE DELIVERY OF AN OPINION OF COUNSEL, CERTIFICATION AND/OR OTHER INFORMATION SATISFACTORY TO EACH OF THEM, AND IN EACH OF THE FOREGOING CASES, A CERTIFICATE OF TRANSFER IN THE FORM APPEARING ON THE OTHER SIDE OF THIS SECURITY IS COMPLETED AND DELIVERED BY THE TRANSFEROR TO THE TRUSTEE. THIS LEGEND WILL BE REMOVED UPON THE REQUEST OF THE HOLDER AFTER THE RESALE RESTRICTION TERMINATION DATE.

THE HOLDER OF THIS SECURITY IS ENTITLED TO THE BENEFITS OF A REGISTRATION RIGHTS AGREEMENT (AS SUCH TERM IS DEFINED IN THE INDENTURE REFERRED TO ON THE REVERSE HEREOF) AND, BY ITS ACCEPTANCE HEREOF, AGREES TO BE BOUND BY AND TO COMPLY WITH THE PROVISIONS OF SUCH REGISTRATION RIGHTS AGREEMENT.

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LEXAR MEDIA, INC.

5.625% SENIOR CONVERTIBLE NOTES DUE 2010

Lexar Media, Inc., a Delaware corporation (the “Company”, which term shall include any successor corporation under the Indenture referred to on the reverse hereof), promises to pay to CEDE & CO., or registered assigns, the principal sum of SIXTY MILLION DOLLARS ($60,000,000) on April 1, 2010 or such greater or lesser amount as is indicated on the Schedule of Exchanges of Securities on the other side of this Security.

Interest Payment Dates: September 30 and March 31.

Regular Record Dates: September 15 and March 15.

This Security is convertible as specified on the other side of this Security. Additional provisions of this Security are set forth on the other side of this Security.

SIGNATURE PAGE FOLLOWS

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IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed.

Dated: March 30, 2005

Trustee’s Certificate of Authentication: This is one of the Securities referred to in the within-mentioned Indenture.

U.S. Bank National Association,

as Trustee

REVERSE SIDE OF NOTE

LEXAR MEDIA, INC.

5.625% SENIOR CONVERTIBLE NOTES DUE 2010

1. INTEREST

Lexar Media, Inc., a Delaware corporation (the “Company”, which term shall include any successor corporation under the Indenture hereinafter referred to), promises to pay interest on the principal amount of this Security at the rate of 5.625% per annum. The Company shall pay interest semiannually in arrears on September 30 and March 31 of each year, commencing September 30, 2005. Interest on the Securities shall accrue from the most recent date to which interest has been paid or, if no interest has been paid, from March 30, 2005; provided, however, that if there is not an existing default in the payment of interest and if this Security is authenticated between a Regular Record Date referred to on the face hereof and the next succeeding Interest Payment Date, interest shall accrue from such Interest Payment Date. Interest will be computed on the basis of a 360-day year, comprised of twelve 30-day months. Any reference herein to interest accrued or payable as of any date shall include any Registration Default Payments accrued or payable on such date as provided in the Registration Rights Agreement.

No sinking fund is provided for the Securities.

2. METHOD OF PAYMENT

The Company shall pay interest on this Security (except defaulted interest) to the person who is the Holder of this Security at the close of business on September 15 or March 15, as the case may be, (each, a Regular Record Date) immediately preceding the related Interest Payment Date. The Holder must surrender this Security to a Paying Agent to collect payment of principal. The Company will pay principal and interest in money of the United States that at the time of payment is legal tender for payment of public and private debts. The Company may, however, pay principal and interest in respect of any Certificated Security by check or wire payable in such money; provided, however, that a Holder with an aggregate principal amount in excess of $2,000,000 will be paid by wire transfer in immediately available funds at the election of such Holder if such Holder has provided wire transfer instructions to the Company. The Company may mail an interest check to the Holder’s registered address. Notwithstanding the foregoing, so long as this Security is registered in the name of a Depositary or its nominee, all payments hereon shall be made by wire transfer of immediately available funds to the account of the Depositary or its nominee.

3. PAYING AGENT, REGISTRAR AND CONVERSION AGENT

Initially, U.S. Bank National Association (the “Trustee”, which term shall include any successor trustee under the Indenture hereinafter referred to) will act as Paying Agent, Registrar and Conversion Agent. The Company may change any Paying Agent, Registrar or Conversion Agent without notice to the Holder. The Company or any of its Subsidiaries may, subject to certain limitations set forth in the Indenture, act as Paying Agent or Registrar.

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4. INDENTURE, LIMITATIONS

This Security is one of a duly authorized issue of Securities of the Company designated as its 5.625% Senior Convertible Notes due 2010 (the “Securities”), issued under an Indenture dated as of March 30, 2005 (together with any supplemental indentures thereto, the “Indenture”), between the Company and the Trustee. The terms of this Security include those stated in the Indenture and those required by or made part of the Indenture by reference to the Trust Indenture Act of 1939, as amended, as in effect on the date of the Indenture. This Security is subject to all such terms, and the Holder of this Security is referred to the Indenture and said Act for a statement of them.

The Securities are unsecured obligations of the Company limited to $60,000,000 (subject to increase by up to an additional aggregate principal amount of $10,000,000 in the event the Purchasers (as defined in Purchase Agreement dated March 30, 2005 (the “Purchase Agreement”) between the Company and the Purchasers thereunder) exercise the right to purchase Additional Securities (as defined in the Purchase Agreement) pursuant to the Purchase Agreement) aggregate principal amount. The Indenture does not limit other debt of the Company, secured or unsecured.

5. OPTIONAL REDEMPTION

Prior to March 31, 2008, this Security shall not be redeemable. On or after March 31, 2008, the Company may, at its option, redeem this Security if the Closing Price of the Common Stock exceeds 175% of the Conversion Price for at least 20 Trading Days in any 30 consecutive Trading Day period, including the last day of the period ending on the Trading Day prior to the date the Company delivers the Redemption Notice, appropriately adjusted to take into account the occurrence, during such 30 Trading Day period, of any event described in Sections 4.6 and 4.11 of the Indenture and (ii) on the date that the Company delivers such Redemption Notice through the Redemption Date, the Common Stock issuable upon conversion of the Securities is either (1) covered by a registration statement covering resales thereof that is effective and available for use and is expected to remain effective and available for use for the 30 days following the date of such Redemption Notice or (2) eligible to be resold by non-affiliates pursuant to Rule 144(k) under the Securities Act,, at a Redemption Price equal to 100% of the principal amount of the Securities being redeemed, in each case for cash in whole, or from time to time in part (which must be equal to $1,000 or any integral multiple thereof), plus accrued and unpaid interest to, but excluding, the Redemption Date, plus the Coupon Make-Whole Payment; provided that if the Redemption Date falls after a Regular Record Date and on or before an Interest Payment Date, then the interest will be payable to the Holder in whose names this Security is registered at the close of business on such Regular Record Date. Securities or portions of this Security called for redemption may be converted by the Holder in accordance with the provisions of Article 4 of the Indenture until the close of business on the Business Day prior to the Redemption Date.

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6. NOTICE OF REDEMPTION

Notice of redemption, as set forth in Section 3.3 of the Indenture, will be mailed by first-class mail at least 20 days but not more than 60 days before the Redemption Date to each Holder of Securities to be redeemed at its registered address. Securities in denominations larger than $1,000 may be redeemed in part, but only in whole multiples of $1,000. On and after the Redemption Date, subject to the deposit with the Paying Agent of funds sufficient to pay the Redemption Price plus accrued interest to, but excluding, the Redemption Date, interest shall cease to accrue on Securities or portions of them called for redemption.

7. PURCHASE OF SECURITIES AT OPTION OF HOLDER UPON A FUNDAMENTAL CHANGE

At the option of the Holder and subject to the terms and conditions of the Indenture, the Company shall become obligated to purchase all or any part specified by the Holder (so long as the principal amount of such part is $1,000 or an integral multiple of $1,000 in excess thereof) of the Securities held by such Holder on the Fundamental Change Purchase Date, at a purchase price equal to 100% of the principal amount thereof together with any accrued interest up to, but excluding, the Fundamental Change Purchase Date. The Holder shall have the right to withdraw any Fundamental Change Purchase Notice (in whole or in a portion thereof that is $1,000 or an integral multiple of $1,000 in excess thereof) at any time prior to the close of business on the Business Day immediately preceding the Fundamental Change Purchase Date by delivering a written notice of withdrawal to the Paying Agent in accordance with the terms of the Indenture.

8. CONVERSION

Subject to and upon compliance with the provisions of the Indenture, at the option of the Holder thereof, any Security or portion thereof that is an integral multiple of $1,000 may be converted into fully paid and nonassessable shares (calculated as to each conversion to the nearest 1/100th of a share) of Common Stock of the Company on or prior to the close of business on the Final Maturity Date, unless previously redeemed to the Company or purchased by the Company at the Holders’ option, at the Conversion Rate, determined as provided in the Indenture, in effect at the time of conversion and subject to the adjustments described therein. Each Holder who elects to convert Securities (other than upon a Fundamental Change whereupon the Holder may be entitled to a Make-Whole Premium required by the terms of the Indenture) during the period from and including the date of the applicable Redemption Notice to and including the last Trading Day prior to the Redemption Date specified in such Redemption Notice shall be entitled to receive the Coupon Make-Whole Payment in respect of the Securities so converted.

9. DENOMINATIONS, TRANSFER, EXCHANGE

The Securities are in registered form, without coupons, in denominations of $1,000 and integral multiples of $1,000. A Holder may register the transfer of or exchange Securities in accordance with the Indenture. The Registrar may require a Holder, among other things, to furnish appropriate endorsements and transfer documents and to pay any taxes or other governmental charges that may be imposed in relation thereto by law or permitted by the Indenture.

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10. PERSONS DEEMED OWNERS

The Holder of a Security may be treated as the owner of it for all purposes.

11. UNCLAIMED MONEY

If money for the payment of principal or interest remains unclaimed for two years, the Trustee or Paying Agent will pay the money back to the Company at its written request, subject to applicable unclaimed property law. After that, Holders entitled to money must look to the Company for payment as general creditors unless an applicable abandoned property law designates another person.

12. AMENDMENT, SUPPLEMENT AND WAIVER

Subject to certain exceptions, the Indenture or the Securities may be amended or supplemented with the consent of the Holders of at least a majority in aggregate principal amount of the Securities then outstanding, and an existing default or Event of Default and its consequence or compliance with any provision of the Indenture or the Securities may be waived in a particular instance with the consent of the Holders of a majority in aggregate principal amount of the Securities then outstanding. Without the consent of or notice to any Holder, the Company and the Trustee may amend or supplement the Indenture or the Securities to, among other things, cure any ambiguity, defect or inconsistency or make any other change that does not adversely affect the rights of any Holder.

13. SUCCESSOR ENTITY

When a successor corporation assumes all the obligations of its predecessor under the Securities and the Indenture in accordance with the terms and conditions of the Indenture, the predecessor corporation (except in certain circumstances specified in the Indenture) be released from those obligations.

14. DEFAULTS AND REMEDIES

This Holder of this Security is entitled to certain remedies upon the occurrence of an Event of Default as set out in Article 8 of the Indenture.

15. TRUSTEE DEALINGS WITH THE COMPANY

U.S. Bank, National Association, the Trustee under the Indenture, in its individual or any other capacity, may make loans to, accept deposits from and perform services for the Company or an Affiliate of the Company, and may otherwise deal with the Company or an Affiliate of the Company, as if it were not the Trustee.

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16. NO RECOURSE AGAINST OTHERS

A director, officer, employee or stockholder, as such, of the Company shall not have any liability for any obligations of the Company under the Securities or the Indenture nor for any claim based on, in respect of or by reason of such obligations or their creation. The Holder of this Security by accepting this Security waives and releases all such liability. The waiver and release are part of the consideration for the issuance of this Security.

17. AUTHENTICATION

This Security shall not be valid until the Trustee or an authenticating agent manually signs the certificate of authentication on the other side of this Security.

18. ABBREVIATIONS AND DEFINITIONS

Customary abbreviations may be used in the name of the Holder or an assignee, such as: TEN COM (= tenants in common), TEN ENT (= tenants by the entireties), JT TEN (= joint tenants with right of survivorship and not as tenants in common), CUST (= Custodian) and UGMA (= Uniform Gifts to Minors Act).

All terms defined in the Indenture and used in this Security but not specifically defined herein are defined in the Indenture and are used herein as so defined.

19. INDENTURE TO CONTROL; GOVERNING LAW

In the case of any conflict between the provisions of this Security and the Indenture, the provisions of the Indenture shall control. This Security shall be governed by, and construed in accordance with, the laws of the State of New York.

The Company will furnish to any Holder, upon written request and without charge, a copy of the Indenture. Requests may be made to: Lexar Media, Inc., 47300 Bayside Parkway, Fremont, CA 94538; Attention: General Counsel.

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ASSIGNMENT FORM

To assign this Security, fill in the form below:

I or we assign and transfer this Security to

(Insert assignee’s soc. sec. or tax I.D. no.)

(Print or type assignee’s name, address and zip code)

and irrevocably appoint

agent to transfer this Security on the books of the Company. The agent may substitute another to act for him or her.

*Signature guaranteed by:

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CONVERSION NOTICE

To convert this Security into Common Stock of the Company, check the box:  ¨

To convert only part of this Security, state the principal amount to be converted (must be $1,000 or a integral multiple of $1,000): $                     .

If you want the stock certificate made out in another person’s name, fill in the form below:

____________________________________________________________________________________________________________________

(Insert assignee’s soc. sec. or tax I.D. no.)

____________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________

(Print or type assignee’s name, address and zip code)

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OPTION TO ELECT PURCHASE

UPON A CHANGE IN CONTROL

The undersigned registered owner of this Security hereby irrevocably acknowledges receipt of a notice from Lexar Media, Inc. (the “Company”) as to the occurrence of a Fundamental Change with respect to the Company and requests and instructs the Company to purchase the entire principal amount of this Security, or the portion thereof (which is $1,000 or an integral multiple thereof) below designated, in accordance with the terms of the Indenture referred to in this Security at the Fundamental Change Purchase Price, together with accrued interest to, but excluding, such date, to the registered Holder hereof.

Principal amount to be redeemed

(in an integral multiple of $1,000, if less than all):

NOTICE: The signature to the foregoing Election must correspond to the Name as written upon the face of this Security in every particular, without alteration or any change whatsoever.

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SCHEDULE OF EXCHANGES OF SECURITIES

The following exchanges, purchase, redemptions, purchases or conversions of a part of this global Security have been made:

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CERTIFICATE TO BE DELIVERED UPON EXCHANGE OR REGISTRATION

OF TRANSFER OF RESTRICTED SECURITIES

This certificate relates to $              principal amount of Securities owned in (check applicable box)

¨  book-entry or   ¨  definitive form by                                  (the “Transferor”).

The Transferor has requested a Registrar or the Trustee to exchange or register the transfer of such Securities.

In connection with such request and in respect of each such Security, the Transferor does hereby certify that the Transferor is familiar with transfer restrictions relating to the Securities as provided in Section 2.12 of the Indenture dated as of March 30, 2005 between Lexar Media, Inc. and U.S. Bank National Association., as trustee (the “Indenture”), and the transfer of such Security is being made pursuant to an effective registration statement under the Securities Act of 1933, as amended (the “Securities Act”) (check applicable box) or the transfer or exchange, as the case may be, of such Security does not require registration under the Securities Act because (check applicable box):

Such Security is being transferred pursuant to and in compliance with an exemption from the registration requirements of the Securities Act (other than an exemption referred to above) and as a result of which such Security will, upon such transfer, cease to be a “restricted security” within the meaning of Rule 144 under the Securities Act.

The Transferor acknowledges and agrees that, if the transferee will hold any such Securities in the form of beneficial interests in a global Security which is a “restricted security” within the meaning of Rule 144 under the Securities Act, then such transfer can only be made pursuant to (i) Rule 144A under the Securities Act and such transferee must be a “qualified institutional buyer” (as defined in Rule 144A) or (ii) Regulation S under the Securities Act.