SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* COLVIN DONALD A (Last) (First) (Middle) 5005 EAST MCDOWELL ROAD (Street) PHOENIX AZ 85008 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol ON SEMICONDUCTOR CORP [ ONNN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) Exec VP & CFO
	3. Date of Earliest Transaction (Month/Day/Year) 10/01/2007
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common(1)	10/01/2007		A		150,000(2)	A	$0	318,560	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. On Sept. 26, 2007, the Board of Directors of the Issuer awarded these restricted stock units to the Reporting Person under the Issuer's 2000 Stock Incentive Plan ("Plan"), with an effective grant date of Oct. 1, 2007 and with equal pro rata vesting over a 3-year period beginning on the first anniversary of the grant date, subject to the terms and conditions of the Plan and the relevant award agreement. This award may only be settled in shares of the Issuer's common stock upon vesting. The award was for no consideration other than service as an executive officer of the Issuer.

2. Not reported on this form, since not required, was an award under the Plan of performance-based stock units by the Issuer to the Reporting Person of 120,000 ("PSUs") with an effective grant date of Oct. 1, 2007. The PSUs vest upon the achievement of a range of both specified product revenue and specified gross margins on product revenue targets prior to the end of the fiscal quarter in which the 3rd anniversary of the effective date of the grant falls. If the base-level performance targets are not achieved then no PSUs will vest. The award is subject to the terms and conditions of the Plan and related award agreement, and was made for no consideration other than service as an officer of the Issuer.

Remarks:

Judith A. Boyle is signing on behalf of the Reporting Person pursuant to a Power of Attorney attached herein as an exhibit, colvin2007poa.TXT

	Judith A. Boyle, Attorney-in-Fact	10/03/2007
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

POWER OF ATTORNEY
(Donald A. Colvin)


I hereby appoint Keith D. Jackson, George H. Cave and Judith A. Boyle, and each
of them,
attorney-in-fact for me, each with full power of substitution, to prepare,
execute and deliver on
my behalf reports required to be filed by me pursuant to Section 16 of the
Securities Exchange
Act of 1934, as amended ("Section 16"), and Rule 144 and Rule 145 under the
Securities Act of
1933 (singly or collectively ("Rule 144")), and any and all related documents
and instruments.
Among other things, each attorney-in-fact is authorized to file original reports
  (either
electronically or otherwise), signed by me or on my behalf, on Forms 3, 4 and 5,
  and Form 144
with the Securities and Exchange Commission, any and all related documents and
instruments,
and to provide any necessary copies of such signed forms, documents and
instruments to The
NASDAQ Stock Market and ON Semiconductor Corporation as required by the rules
under
Section 16 and Rule 144 as in effect from time to time.

This power of attorney is effective from the date hereof until April 15, 2008,
unless earlier
revoked or terminated.


/s/ DONALD A. COLVIN
Donald A. Colvin

Dated:	March 1, 2007

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