EXHIBIT 5.1


November 15, 2001
                                            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
    2001 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 1,300,000  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