OPINION OF MARY K. SIMMONS RE: LEGALITY OF SHARES

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