Exhibit 5.1


March 10, 2003
                                            WRITER'S DIRECT LINE: (480) 792-7381
                                       WRITER'S DIRECT FACSIMILE: (480) 792-4112


Microchip Technology Incorporated
2355 West Chandler Boulevard
Chandler, AZ  85224

      Re: Registration Statement on Form S-8 For Issuance of Common Stock Under
          the Microchip Technology Incorporated International Employee Stock
          Purchase Plan (the "Plan")

Gentlemen:

I refer  you to your  registration  on Form S-8 (the  "Registration  Statement")
under the Securities  Act of 1933, as amended,  of 25,000 shares of Common Stock
under the Plan.  I advise you that,  in my  opinion,  when such shares have been
issued  and sold  pursuant  to the  applicable  provisions  of the Plan,  and in
accordance with the Registration Statement,  such shares will be validly issued,
fully-paid and  non-assessable  shares of the Company's  Common Stock, par value
$.001 per share.

I hereby consent to the filing of this opinion as an exhibit to the Registration
Statement.

Sincerely yours,

/s/ Mary K. Simmons

Mary K. Simmons
Vice President, General Counsel
Microchip Technology Incorporated