Exhibit 10.66

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS,
HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

AMENDMENT ONE

TO

WAFER SUPPLY AGREEMENT

This Amendment Number One (the “Amendment”), effective as of July 20, 2005
(“Amendment Date”), amends the Wafer Supply Agreement effective as of May 23,
2003 (the “Agreement”), by and between Power Integrations, Inc. and ZMD Analog
Mixed Signal Services GmbH & CoKG.

RECITALS

The parties to the Agreement hereby agree to amend the Agreement as follows:

AMENDMENT

I. On page 1, substitute the following heading for the heading beginning with
“This Agreement (“Agreement”) is made and entered into as of this 23rd day of
May, 2003,” and ending with (“POWER INTEGRATIONS”).”:

This Agreement (“Agreement”) is made and entered into as of this 23rd day of
May, 2003 (the “Effective Date”), by and between:

 

  (1) Power Integrations International, Ltd., a Cayman Islands corporation
having its principal place of business at P.O. Box 219, Strathvale House, North
Church Street, George Town, Grand Cayman, Cayman Islands (“POWER INTEGRATIONS”);

 

Confidential

1.

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II. Add the following new section to Article I (“Definitions”):

1.23 [*] TECHNOLOGY: The technology described in all documentation listed in
Exhibit D ([*] TECHNOLOGY), including [*] process technology and analog and
digital libraries.

III. Add the following new Section 4.6:

4.6 POWER INTEGRATIONS will pay SUPPLIER a [*] licensee fee of [*] United States
dollars (US $[*] within [*] ([*]) days of the Amendment Date, for which SUPPLIER
hereby grants to POWER INTEGRATIONS a non-exclusive, irrevocable, perpetual,
royalty-free, non-transferable, worldwide, right and license, under all
INTELLECTUAL PROPERTY RIGHTS to use, modify, reproduce, distribute and otherwise
exploit in any manner all [*] TECHNOLOGY as part of the POWER INTEGRATIONS
PROCESS and any modifications thereto. Without any consent of SUPPLIER, POWER
INTEGRATIONS may sublicense the foregoing license to POWER INTEGRATIONS’
SUBSIDIARY so long as the sublicense provides for the protection of SUPPLIER’s
CONFIDENTIAL INFORMATION on terms not less protective of SUPPLIER’s rights than
those set forth in this Agreement. SUPPLIER will promptly disclose in writing
all [*] TECHNOLOGY to POWER INTEGRATIONS upon payment of such [*] license fee.

IV. Add the updated Exhibit B (PRICES), attached.

V. Add the new Exhibit D ([*] TECHNOLOGY), attached.

 

Confidential

2.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS,
HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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VI. The following changes are only to correct various minor clerical errors and
do not change the intent or the meaning of the agreement.

In each instance in the Agreement, change “SUPPLIER’s” to “SUPPLIER’S”.

In Section 1.9 change “POWER INTEGRATIONS, INC.” to “POWER INTEGRATIONS.”

In Section 4.4, after “may sublicense the”, insert “foregoing license for the”.

In Section 5.1.1, delete “an order” and substitute “a PO”.

In Section 5.1.2, after “The output”, insert “of the PILOT PRODUCTION”.

In Section 5.2.1 delete “an order” and substitute “a PO”.

In Section 11.1 delete “such”.

In Section 12.2 (d) delete “or”.

In Section 12.2(e) after “Agreement” delete the period and add “;or”.

In Section 12.2 (f) change “a Disclosing Party” to “the disclosing party”.

In the paragraph after Section 12.2(f) change:

“that Recipient” to “that the receiving party”;

“the Recipient must” to “the receiving party must”; and

“to such a disclosure” to “to any such disclosure”.

In the first line of Section 13.4 change “A first” to “Either”.

 

Confidential

3.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS,
HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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IN WITNESS WHEREOF, the undersigned parties have caused this Amendment to be
executed by their duly authorized representatives.

 

ZMD ANALOG MIXED SIGNAL SERVICES GMBH & COKG.     POWER INTEGRATIONS, INC. By:  

/s/ Konrad Herre

    By:  

/s/ Balu Balakrishnan

Name:  

KONRAD HERRE

    Name:   BALU BALAKRISHNAN Title:  

GESCHÄFTSFÜHRER 

    Title:   C.E.O. AND PRESIDENT       POWER INTEGRATIONS INTERNATIONAL, LTD.  
    By:  

/s/ John L. Tomlin

      Name:   JOHN L. TOMLIN       Title:   PRESIDENT AND DIRECTOR

 

Confidential

4.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS,
HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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Exhibit B

Effective as of July 1, 2005

PRICES

[*] DC PROCESS WAFER

 

Price:        

   [*] layers    [*]

A rebate of [*] dollars ($[*]) shall be applied to each WAFER purchased by PI
until [*] ([*]) WAFERS have been accepted by PI.

Delivery times:

 

VOLUME PRODUCTION

   [*]   

DC PROCESS ENGINEERING WAFER

 

Price:    Std. and non-std. run    [*]    Hot run    [*]    Minimum wafer lot
size    [*] Delivery times:    Standard run    [*]    Hot run    [*]   
Non-Standard run    [*] MASK TOOLING SET Price:    [*] mask set      
                ([*][*] masks)                       ([*] [*] masks)    [*]   
Individual masks                               [*] mask [*]      
                        [*] mask [*]       Vendors: [*]   

ALL PRICES ABOVE WILL BE NEGOTIATED AND PAID IN US DOLLARS.

 

Confidential

5.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS,
HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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Exhibit D

[*] INCH TECHNOLOGY

1. [*] Technology documentation

 

Documents:

  

        Doc. Nr.        

    

        Date        

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

[*]

   [*]      [*]

Forms:

           

[*]

   [*]      [*]    [*]      [*]    [*]      [*]    [*]      [*]    [*]     

 

Confidential

6.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS,
HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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2. [*] Design Documentation and Digital Library

 

[*]

   [*]    [*]    [*]    [*]    [*]    [*]    [*]    [*]    [*]    [*]    [*]   
[*]

[*]

   [*]    [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]    [*]    [*]    [*]    [*]    [*]    [*]   
[*]

[*]

   [*]    [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]    [*]

 

version

   TechLib release   compatible
AssuraRules release   compatible
CellLibs release

[*]

   [*]   [*]   [*]

[*]

   [*]   [*]   [*]

[*]

   [*]   [*]   [*]

 

Confidential

7.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS,
HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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(a)    Miscellaneous Development Documents

•     [*]

  

•     [*]

     

(b)    [*] Documents

•     [*]

  

•     [*]

  

•     [*]

  

•     [*]

  

 

Confidential

8.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS,
HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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3. [*] Analog Library

 

Function

  

IR-Cell Name

  

Technology

  

Preliminary Specification

  

Status

  

Silicon

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]       [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]    [*]    [*]       [*]    [*]    [*]    [*]
      [*]    [*]    [*]    [*]       [*]    [*]    [*]    [*]       [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

 

Confidential

9.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS,
HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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[*]

   [*]    [*]    [*]    [*]    [*]    [*]    [*]       [*]    [*]    [*]    [*]
      [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]    [*]    [*]       [*]    [*]    [*]    [*]
      [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]    [*]    [*]       [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]

[*]

   [*]    [*]    [*]    [*]    [*]    [*]    [*]       [*]    [*]    [*]    [*]
      [*]    [*]    [*]    [*]       [*]    [*]    [*]    [*]       [*]    [*]

 

Confidential

10.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS,
HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.