Exhibit 10.4

FIRST AMENDMENT TO CREDIT AGREEMENT

THIS AMENDMENT TO CREDIT AGREEMENT (this "Amendment") is entered into as of
August 2, 2011, by and between POWER INTEGRATIONS, INC., a Delaware corporation
("Borrower"), and WELLS FARGO BANK, NATIONAL ASSOCIATION ("Bank").

RECITALS

WHEREAS, Borrower is currently indebted to Bank pursuant to the terms and
conditions of that certain Credit Agreement between Borrower and Bank dated as
of February 22, 2011, as amended from time to time ("Credit Agreement").

WHEREAS, Bank and Borrower have agreed to certain changes in the terms and
conditions set forth in the Credit Agreement and have agreed to amend the Credit
Agreement to reflect said changes.

NOW, THEREFORE, for valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the parties hereto agree that the Credit Agreement
shall be amended as follows:
1.
Section 1.1(b) is hereby deleted in its entirety, and the following substituted
therefor:

“(b)     Letter of Credit Subfeature. As a subfeature under the Line of Credit,
Bank agrees from time to time during the term thereof to issue or cause an
affiliate to issue commercial and standby letters of credit for the account of
Borrower to back performance (each, a "Letter of Credit" and collectively,
"Letters of Credit"); provided however, that the aggregate undrawn amount of all
outstanding Letters of Credit shall not at any time exceed Twenty Million
Dollars ($20,000,000.00). Unless cash secured to Bank's satisfaction, no Letter
of Credit shall have an expiration date subsequent to the maturity date of the
Line of Credit. The undrawn amount of all Letters of Credit shall be reserved
under the Line of Credit and shall not be available for borrowings thereunder.
Each Letter of Credit shall be subject to the additional terms and conditions of
the Letter of Credit agreements, applications and any related documents required
by Bank in connection with the issuance thereof. Each drawing paid under a
Letter of Credit shall be deemed an advance under the Line of Credit and shall
be repaid by Borrower in accordance with the terms and conditions of this
Agreement applicable to such advances; provided however, that if advances under
the Line of Credit are not available, for any reason, at the time any drawing is
paid, then Borrower shall immediately pay to Bank the full amount drawn,
together with interest thereon from the date such drawing is paid to the date
such amount is fully repaid by Borrower, at the rate of interest applicable to
advances under the Line of Credit. In such event Borrower agrees that Bank, in
its sole discretion, may debit any account maintained by Borrower with Bank for
the amount of any such drawing.”

2. Section 1.2 (c) is hereby deleted in its entirety, and the following
substituted therefor:

“(c) Standby and Commercial Letter of Credit Fees. Borrower shall pay to Bank
(i) fees upon the issuance of each Standby and Commercial Letter of Credit equal
to one and one quarter percent (1.25%) per annum (computed on the basis of a
360-day year, actual days elapsed) of the face amount thereof, and (ii) fees
upon the payment or negotiation of each
drawing under any Standby and Commercial Letter of Credit and fees upon the
occurrence of any other activity with respect to any Standby and Commercial
Letter of Credit (including without limitation, the transfer, amendment or
cancellation of any Standby and Commercial Letter of Credit) determined in
accordance with Bank's standard fees and charges then in effect for such
activity.”

3. Except as specifically provided herein, all terms and conditions of the
Credit Agreement remain

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in full force and effect, without waiver or modification. All terms defined in
the Credit Agreement shall have the same meaning when used in this Amendment.
This Amendment and the Credit Agreement shall be read together, as one document.

4. Borrower hereby remakes all representations and warranties contained in the
Credit Agreement and reaffirms all covenants set forth therein. Borrower further
certifies that as of the date of this Amendment there exists no Event of Default
as defined in the Credit Agreement, nor any condition, act or event which with
the giving of notice or the passage of time or both would constitute any such
Event of Default.

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
as of the day and year first written above.

POWER INTEGRATIONS, INC.
 
WELLS FARGO BANK,
 
 
 
NATIONAL ASSOCIATION
By:
/s/ Balu Balakrishnan
 
By:
/s/ Greg P. Cohn
 
Balu Balakrishnan,
 
 
Greg P. Cohn,
 
President & CEO
 
 
Vice President

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