<PAGE>
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
Under the Securities Exchange Act of 1934
(Amendment No. 10)*
Microsemi Corporation
-----------------------------
(Name of Issuer)
Common Stock, par value $.20 per share
-------------------------------------------------
(Title of Class of Securities)
940-570
---------------
(CUSIP Number)
*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.
The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).
Page 1 of 4 Pages
<PAGE>
1 NAME OF REPORTING PERSON
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
Philip Frey, Jr.
- ------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [_]
(b) [_]
- ------------------------------------------------------------------------------
3 SEC USE ONLY
- ------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
United States
- ------------------------------------------------------------------------------
NUMBER 5 SOLE VOTING POWER
OF SHARES 956,953 (includes 23,400 shares issuable upon conversion of
BENEFICIALLY convertible securities or option exercises within 60 days)
OWNED BY ---------------------------------------------------------------
EACH 6 SHARED VOTING POWER
REPORTING 0
PERSON ---------------------------------------------------------------
WITH 7 SOLE DISPOSITIVE POWER
956,953 (includes 23,400 shares issuable upon conversion of
convertible securities or option exercises within 60 days)
----------------------------------------------------------------
8 SHARED DISPOSITIVE POWER
0
- -------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
956,953 (includes 23,400 shares issuable upon conversion of
convertible securities or option exercises within 60 days)
- -------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
[_]
- -------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
8.4%
- ------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON*
IN
- ------------------------------------------------------------------------------
*SEE INSTRUCTION BEFORE FILLING OUT!
Page 2 of 4 Pages
<PAGE>
Item 1(a) Name of Issuer:
- -----------------------------------
MICROSEMI CORPORATION
Item 1(b) Address of Issuer's Principal Executive Offices:
- ------------------------------------------------------------
2830 South Fairview Street
Santa Ana, CA 92704
Mailing address:
P.O. Box 26890
Santa Ana, CA 92799-6890
Item 2(a) Name of Person Filing:
- ----------------------------------
Philip Frey, Jr.
Item 2(b) Address of Principal Business Office or, if none, Residence:
- -------------------------------------------------------------------------
2830 South Fairview Street
Santa Ana, CA 92704
Item 2(c) Citizenship:
- -------------------------
United States
Item 2(d) Title of Class of Securities:
- -----------------------------------------
(i) Common Stock, $.20 par value
Item 2(e) CUSIP Number:
- -------------------------
(i) 940-570
Item 3 If this statement is filed pursuant to Rule 13d-1(b), or 13d-2(b),
check whether the person filing is a:
- -------------------------------------------------------------------------
(a) [_] Broker or Dealer registered under Section 15 of the Act
(b) [_] Bank as defined in section 3(a)(6) of the Act
(c) [_] Insurance Company as defined in section 3(a)(9) of the Act
(d) [_] Investment Company registered under section 8 of the
Investment Company Act
(e) [_] Investment Adviser registered under section 203 of the
Investment Advisers Act of 1940
(f) [_] Employee Benefit Plan, Pension Fund which is subject to the
provisions of the Employee Retirement Income Security Act of
1974 or Endowment Fund: see Section 240.13d-1(b)(1)(ii)(F)
(g) [_] Parent Holding Company, in accordance with
Section 240.13d-1(b)(ii)(G) (Note: See Item 7)
(h) [_] Group, in accordance with Section 240.13d-1(b)(1)(ii)(H)
Page 3 of 4 Pages
<PAGE>
Item 4 Ownership:
- -----------------
(a) Amount Beneficially owned: 956,953
(b) Percent of Class: 8.4%
(c) Number of shares as to which such corporation has:
(i) sole power to vote or to direct the vote: 956,953
(ii) shared power to vote or to direct the vote: 0
(iii) sole power to dispose or to direct the disposition of: 956,953
(iv) shared power to dispose or to direct the disposition of: 0
Item 5 Ownership of Five Percent or Less of a Class:
- -----------------------------------------------------
Not Applicable
Item 6 Ownership of More than Five Percent on Behalf of Another:
- -----------------------------------------------------------------
Not Applicable
Item 7 Identification and Classification of the Subsidiary Which Acquired the
Security Being Reported on By the Parent Holding Company:
- ---------------------------------------------------------
Not Applicable
Item 8 Identification and Classification of Members of the Group:
- ------------------------------------------------------------------
Not Applicable
Item 9 Notice of Dissolution of Group:
- ---------------------------------------
Not Applicable
Item 10 Certification:
- -----------------------
Not Applicable
Signature:
- -----------
After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.
February 18, 1999
- ---------------------------------
Date
/s/ PHILIP FREY, JR.
- ---------------------------------
Signature
Philip Frey, Jr., Individually
- ---------------------------------
Name/Title
Page 4 of 4 Pages