OPINION OF WILSON SONSINI GOODRICH & ROSATI

EXHIBIT 5.1

OPINION OF WILSON SONSINI GOODRICH & ROSATI, PROFESSIONAL CORPORATION

December 6, 1999

Microchip Technology Incorporated
2355 West Chandler Boulevard
Chandler, AZ 85224-6199

Re: Registration Statement on Form S-3

Ladies and Gentlemen:

We have examined the Registration Statement on Form S-3 to be filed by you
with the Securities and Exchange Commission on or about December 7, 1999 (as
such may thereafter be amended or supplemented, the "Registration Statement")
in connection with the registration under the Securities Act of 1933, as
amended, of 1,265,000 shares of your Common Stock, $.001 par value (the
"Stock"). The Stock includes 1,265,000 shares to be issued by the Company
including an over-allotment option granted to the Underwriters to purchase
165,000 shares. As your legal counsel, we have examined the proceedings being
taken by you relating to the issuance and sale of the Stock.

It is our opinion that the Stock, when issued and sold in the manner
referred to in the Registration Statement and in accordance with the
resolutions adopted by the Board of Directors of the Company, will be legally
and validly issued, fully paid and nonassessable.

We consent to the use of this opinion as an exhibit to the Registration
Statement and further consent to the use of our name wherever appearing in the
Registration Statement, including the Prospectus constituting a part thereof,
and any amendments thereto.

Very truly yours,

WILSON SONSINI GOODRICH & ROSATI
Professional Corporation

/s/ Wilson Sonsini Goodrich &
Rosati, Professional Corporation