THEEXECUTIVE NONQUALIFIED EXCESS PLAN

Exhibit 10.12

THE EXECUTIVE

NONQUALIFIED “EXCESS” PLAN^™

ADOPTION AGREEMENT

THIS AGREEMENT is made the 1^st day of January, 2004, by Semtech Corporation (the “Employer”), having its principal office at 200 Flynn Rd., Camarillo, CA 93012 and EXECUTIVE BENEFIT SERVICES, INC. (the “Sponsor”), having its principal office at 4140 ParkLake Avenue, Suite 500, Raleigh, NC 27612.

W I T N E S S E T H:

WHEREAS, the Sponsor has established The Executive Nonqualified Excess Plan^™ (the “Plan”); and

WHEREAS, the Employer desires to adopt the Plan as an unfunded, nonqualified deferred compensation plan: and

WHEREAS, the Employer has been advised by the Sponsor to obtain legal and tax advice from its professional advisors before adopting the Plan, and that the Sponsor disclaims all liability for the legal and tax consequences which result from the elections made by the Employer in this Adoption Agreement;

NOW, THEREFORE, the Employer hereby adopts the Plan in accordance with the terms and conditions set forth in this Adoption Agreement:

ARTICLE I

Terms used in this Adoption Agreement shall have the same meaning as in the Plan, unless some other meaning is expressly herein set forth. The Employer hereby represents and warrants that the Plan has been adopted by the Employer upon proper authorization and the Employer hereby elects to adopt the Plan for the benefit of its Participants as referred to in the Plan. By the execution of this Adoption Agreement, the Employer hereby agrees to be bound by the terms of the Plan.

This Adoption Agreement may only be used in connection with The Executive Nonqualified Excess Plan^™. The Sponsor will inform the Employer of any amendments to the Plan or of the discontinuance or abandonment of the Plan. For questions concerning the Plan, the Employer may call the Sponsor at ###-###-####.

© 2003 Executive Benefit Services, Inc.

ARTICLE II

The Employer hereby makes the following designations or elections for the purpose of the Plan [Section references below correspond to Section references in the Plan]:

2.7 Compensation: The “Compensation” of a Participant shall mean all of each Participant’s [check desired option(s)]:

Notwithstanding the foregoing, Compensation x SHALL ¨ SHALL NOT include Salary Deferral Credits under this Plan and amounts contributed by the Participant pursuant to a Salary Deferral Agreement to another employee benefit plan of the Employer which are not includible in the gross income of the Employee under Section 125, 132(f)(4), 402(e)(3), 402(h) or 403(b) of the Code.

2.8 Crediting Date: The Deferred Compensation Account of a Participant shall be credited with the amount of any Salary Deferral Credits to such account at the time designated below [check desired Crediting Date]:

2.10 Disability: The disability of a Participant shall be determined as follows:

2.14 Effective Date [check desired option]:

2.20 Normal Retirement Date: The Normal Retirement Date of a Participant shall be: [check desired option]:

2.22 Participating Employer(s): As of the Effective Date, the following Participating Employer(s) are parties to the Plan [list all employer-parties, including the Employer]:

2.23 Plan: The name of the Plan as applied to the Employer is:

Semtech Executive Compensation Plan.

2.24 Plan Administrator: The Plan Administrator shall be [check desired option]:

2.25 Plan Year: The Plan Year shall be the 12 consecutive calendar month period ending on the last day of the month of December, and each anniversary thereof.

2.34 Trust: [check desired option]:

4.1 Salary Deferral Credits: A Participant may elect to have his Compensation (as selected in Section 2.7 of this Adoption Agreement) reduced by the following annual percentage or amount as designated in writing to the Committee [check the applicable options]:

4.1.2 Termination of Salary Deferrals: A Participant may terminate his Salary Deferral Agreement effective as of [check desired option]:

4.2 Employer Credits: The Employer will make Employer Credits in the following manner [check a maximum of 2 desired option(s)]:

5.1 Death of a Participant: If the Participant dies while in Service, the Employer shall pay a benefit to the Beneficiary in an amount equal to the Accrued Benefit of the Participant determined as of the date payments to the Beneficiary commence, plus [check if desired]:

6.1 In-Service Withdrawals: In-service withdrawals may be made from the Plan [check desired option]:

6.2 Financial Hardship Withdrawals: Financial hardship withdrawals may be made from the Plan [check desired option]:

6.3 “Haircut” Withdrawals: “Haircut” withdrawals may be made from the Plan [check desired option]:

6.4 Education Withdrawals: Education withdrawals may be made from the Plan [check desired option]:

7.1 Payment Options: Any benefit payable under the Plan upon a Qualifying Distribution Event may be made to the Participant or his Beneficiary (as applicable) in any of the following payment forms, as selected by the Participant upon his entry into the Plan [check desired option(s)]:

8. Vesting: An Active Participant shall be fully vested in the Employer Credits made to the Deferred Compensation Account upon occurrence of the following events [check or complete all that apply]:

10. Benefit Exchange: The Employer elects to permit the Participant to exchange all or any portion of the vested Accrued Benefit under the Plan for another type of nonqualified benefit [check desired option]:

11. Transfer to Qualified Plan: The Employer elects to permit the Participant to direct the transfer of a portion of his benefit under this Plan to a tax-qualified retirement plan maintained by the Employer [check desired option]:

17. Amendment or Termination of Plan: [check or complete all that apply]:

IN WITNESS WHEREOF, this Agreement has been executed as of the day and year first above stated.

NOTE: Execution of this Adoption Agreement creates a legal liability of the Employer with significant tax consequences to the Employer and Participants. The Employer should obtain legal and tax advice from its professional advisors before adopting the Plan. The Sponsor disclaims all liability for the legal and tax consequences which result from the elections made by the Employer in this Adoption Agreement.

The Plan is adopted by the following Participating Employers: