ON SEMICONDUCTOR CORP — Director's Dealing 2010

Mar 1, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ON SEMICONDUCTOR CORP (ONNN)
CIK: 0001097864
Period of Report: 2010-02-25

Reporting Person: CAVE GEORGE H (SVP, Gen Cnsl, CC&EO, & Sec)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-02-25	Common	A	31519	$7.99	Acquired	93900	Direct
2010-02-25	Common	F	10360	$7.99	Disposed	83540	Direct
2010-03-01	Common	S	12000	$8.1114	Disposed	71540	Direct

Footnotes

F1: This transaction reports the acquisition, effective February 25, 2010, of 31,519 shares of common stock resulting from the attainment of a performance goal under an earlier Performance Based Restricted Stock Units Award ("PBRSU Award"), as described more below. The Compensation Committee of the Issuer originally awarded 378,223 PBRSUs to the Reporting Person with an effective grant date of March 2, 2009 subject to the Issuers 2000 Stock Incentive Plan and a related award agreement. The PBRSU Award will vest, generally, over a three-year (twelve quarter) period but only upon the Issuer achieving certain adjusted non-GAAP earnings before interest, taxes, depreciation and amortization ("EBITDA") base and target performance measurements as set forth in the PBRSU Award agreement.

F2: Includes 500 shares acquired by Reporting Person under Issuer's Employee Stock Purchase Plan from 10/1/2009 through 12/31/2009.

F3: This transaction reports the disposition of shares of common stock withheld by the Issuer in connection with the vesting of the PBRSU Award explained in (1) above. This withholding is pursuant to the related award agreement in order to satisfy the Reporting Person's tax obligations due upon the vesting of the units. The Issuer will pay the taxes on behalf of the Reporting Person.

F4: This transaction was made pursuant to the Reporting Person's existing Rule 10b5-1 Plan (i.e. a stock trading plan designed to comply with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended). This disposition transaction was executed in multiple trades at prices ranging from $8.11 to $8.12. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide, upon request, to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.