UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G
                    Under the Securities Exchange Act of 1934
 


                            Power Integrations, Inc.
-------------------------------------------------------------------------------
                                (Name of Issuer)



                          Common Stock, $.001 par value
-------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                    739276103
                  --------------------------------------------
                                 (CUSIP Number)




                                December 31, 2004
-------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)


Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

[X] Rule 13d-1(b)

[_] Rule 13d-1(c)

[_] Rule 13d-1(d)



                                Page 1 of 7 pages



-----------------------
  CUSIP No. 739276103                  13G
-----------------------

------------------------------------------------------------------------------
 1.   Name of Reporting Person
      I.R.S. Identification No. of above Person

           Goldman Sachs Asset Management, L.P.


------------------------------------------------------------------------------
 2.   Check the Appropriate Box if a Member of a Group
                                                                (a) [_]
                                                                (b) [_]

------------------------------------------------------------------------------
 3.   SEC Use Only
 


------------------------------------------------------------------------------
 4.   Citizenship or Place of Organization
 
           Delaware

------------------------------------------------------------------------------
                     5.   Sole Voting Power
 
     Number of                 1,597,771

      Shares        ----------------------------------------------------------
                     6.   Shared Voting Power
   Beneficially
                               0
     Owned by
                    ----------------------------------------------------------
       Each          7.   Sole Dispositive Power
 
    Reporting                  1,620,198

      Person        ----------------------------------------------------------
                     8.   Shared Dispositive Power
       With:
                               0

------------------------------------------------------------------------------
 9.   Aggregate Amount Beneficially Owned by Each Reporting Person
 
           1,620,198

------------------------------------------------------------------------------
10.   Check if the Aggregate Amount in Row (9) Excludes Certain Shares

                                                                    [_]

------------------------------------------------------------------------------
11.   Percent of Class Represented by Amount in Row (9)

           5.2%

------------------------------------------------------------------------------
12.   Type of Reporting Person

           IA

------------------------------------------------------------------------------

 


                               Page 2 of 7 pages


Item 1(a).         Name of Issuer:
                   Power Integrations, Inc.

Item 1(b).         Address of Issuer's Principal Executive Offices:
                   5245 Hellyer Avenue
                   San Jose, CA 95138
                    
Item 2(a).         Name of Persons Filing:
                   Goldman Sachs Asset Management, L.P. 

Item 2(b).         Address of Principal Business Office or, if none, Residence:
                   32 Old Slip
                   New York, NY 10005

Item 2(c).         Citizenship:
                   Goldman Sachs Asset Management, L.P. - Delaware
                   
Item 2(d).         Title of Class of Securities:
                   Common Stock, $.001 par value

Item 2(e).         CUSIP Number:
                   739276103

Item 3.            If this statement is filed pursuant to Rules 13d-1(b) or
                   13d-2(b) or (c), check whether the person filing is a :

          (a).[ ]  Broker or dealer registered under Section 15 of the Act
                   (15 U.S.C. 78o).

          (b).[_]  Bank as defined in Section 3(a)(6) of the Act
                   (15 U.S.C. 78c).

          (c).[_]  Insurance company as defined in Section 3(a)(19) of the Act
                   (15 U.S.C. 78c).

          (d).[_]  Investment company registered under Section 8 of the
                   Investment Company Act of 1940 (15 U.S.C. 80a-8);
                   
          (e).[X]  An investment adviser in accordance with
                   Rule 13d-1(b)(1)(ii)(E);

          (f).[_]  An employee benefit plan or endowment fund in accordance
                   with Rule 13d-1(b)(1)(ii)(F);

          (g).[_]  A parent holding company or control person in accordance
                   with Rule 13d-1(b)(1)(ii)(G);

          (h).[_]  A savings association as defined in Section 3(b) of the
                   Federal Deposit Insurance Act (12 U.S.C. 1813);

          (i).[_]  A church plan that is excluded from the definition of an
                   investment company under Section 3(c)(14) of the
                   Investment Company Act of 1940 (15 U.S.C. 80a-3);

          (j).[_]  Group, in accordance with Rule 13d-1(b)(1)(ii)(J).




                              Page 3 of 7 pages


Item 4.            Ownership.(*)

          (a).     Amount beneficially owned:
                   See the response(s) to Item  9 on the attached cover page(s).

          (b).     Percent of Class:
                   See the response(s) to Item 11 on the attached cover page(s).

          (c).     Number of shares as to which such person has:

                   (i).     Sole power to  vote or to direct  the vote:  See the
                            response(s) to Item 5 on the attached cover page(s).
 
                   (ii).    Shared power to vote or to direct the vote:  See the
                            response(s) to Item 6 on the attached cover page(s).
 
                   (iii).   Sole power to  dispose or to direct  the disposition
                            of:  See the response(s) to  Item 7  on the attached
                            cover page(s).

                   (iv).    Shared power to dispose or to direct the disposition
                            of:  See the response(s) to  Item 8  on the attached
                            cover page(s).

Item 5.            Ownership of Five Percent or Less of a Class.
                             Not Applicable

Item 6.            Ownership of More than Five Percent on Behalf of Another
                   Person.
                             Not Applicable

Item 7.            Identification  and  Classification  of the Subsidiary  Which
                   Acquired the Security Being Reported on by the Parent Holding
                   Company.
                             Not Applicable

Item 8.            Identification and Classification of Members of the Group.
                             Not Applicable

Item 9.            Notice of Dissolution of Group.
                             Not Applicable

Item 10.           Certification.
                   By signing  below I certify that, to the best of my knowledge
                   and belief,  the  securities  referred to above were acquired
                   and are held in the ordinary  course of business and were not
                   acquired  and are not  held  for the  purpose  of or with the
                   effect of changing or  influencing  the control of the issuer
                   of the  securities  and were not acquired and are not held in
                   connection with or as a participant in any transaction having
                   that purpose or effect.


--------------------------
     (*) In accordance with Securities and Exchange  Commission  ("SEC") Release
No.   34-39538   (January  12,  1998),   this  filing  reflects  the  securities
beneficially owned by Goldman Sachs Asset Management, L.P. ("GSAM LP"). GSAM LP,
an investment advisor, disclaims beneficial ownership of any securities managed,
on GSAM LP's behalf, by third parties.





                              Page 4 of 7 pages



                                    SIGNATURE


            After reasonable inquiry and to the best of my knowledge
            and belief,  I certify that the information set forth in
            this statement is true, complete and correct.


Date:  February 7, 2005



                                GOLDMAN SACHS ASSET MANAGEMENT, L.P. 




                                By: /s/ Ted Chang
                                   ----------------------------------------
                                Name:   Ted Chang
                                Title:  Attorney-in-fact





                              Page 5 of 7 pages


 
                                INDEX TO EXHIBITS


Exhibit No.   Exhibit
-----------   -------


  99.1                Power of Attorney, dated November 19, 2003,  relating to
                      Goldman Sachs Asset Management, L.P.




                              Page 6 of 7 pages



                                                                  EXHIBIT (99.1)



                                POWER OF ATTORNEY


     KNOW ALL PERSONS BY THESE  PRESENTS  that GOLDMAN  SACHS ASSET  MANAGEMENT,
L.P. (the "Company")  does hereby make,  constitute and appoint each of Roger S.
Begelman, Edward T. Joel, Saskia Brookfield Martin and Ted Chang, (and any other
employee of The Goldman Sachs Group, Inc. or one of its affiliates designated in
writing  by one of the  attorneys-in-fact),  acting  individually,  its true and
lawful  attorney,  to execute and deliver in its name and on its behalf  whether
the Company is acting  individually or as representative of others,  any and all
filings required to be made by the Company under the Securities  Exchange Act of
1934, (as amended, the "Act"), with respect to securities which may be deemed to
be  beneficially  owned by the Company  under the Act,  giving and granting unto
each said  attorney-in-fact  power and authority to act in the premises as fully
and to all intents and purposes as the Company  might or could do if  personally
present by one of its authorized  signatories,  hereby  ratifying and confirming
all that said  attorney-in-fact  shall lawfully do or cause to be done by virtue
hereof.

     THIS POWER OF ATTORNEY  shall  remain in full force and effect until either
revoked  in  writing  by the  undersigned  or until  such time as the  person or
persons to whom power of  attorney  has been  hereby  granted  cease(s) to be an
employee of The Goldman Sachs Group, Inc. or one of its affiliates.

     IN WITNESS  WHEREOF,  the undersigned has duly subscribed these presents as
of November 19th, 2003.


GOLDMAN SACHS ASSET MANAGEMENT, L.P.


By: s/ Howard Surloff
----------------------------
Name:  Howard Surloff
Title: Managing Director




                              Page 7 of 7 pages