January 25, 2001                                                    EXHIBIT 18.1



Board of Directors
Microsemi Corporation
2830 South Fairview Street
Santa Ana, California  92704

Dear Directors:

We are providing this letter to you for inclusion as an exhibit to your Form
10-Q filing pursuant to Item 601 of Regulation S-K.

We have been provided a copy of the Company's Quarterly Report on Form 10-Q for
the quarterly period ended December 31, 2000. Note 2 therein describes a change
in accounting principle from the last-in, first-out ("LIFO") inventory method to
the first-in, first-out inventory method at Microsemi Corporation - Scottsdale,
a subsidiary of the Company. It should be understood that the preferability of
one acceptable method of accounting over another for the determination of the
costing of inventory has not been addressed in any authoritative accounting
literature and, in expressing our concurrence below, we have relied on
management's determination that this change in accounting principle is
preferable. Based on our reading of management's stated reasons and
justification for this change in accounting principle in the Form 10-Q, and our
discussions with management as to their judgment about the relevant business
planning factors relating to the change, we concur with management that such
change represents, in the Company's circumstances, the adoption of a preferable
accounting principle in conformity with Accounting Principles Board Opinion No.
20.

We have not audited any consolidated financial statements of the Company as of
any date or for any period subsequent to October 1, 2000.  Accordingly, our
comments are subject to change upon completion of an audit of the consolidated
financial statements covering the period of the accounting change.

Very truly yours,

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP