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: Hall William (Sr VP & GM, Std Prod Grp)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-02-25	Common	A	20525	$7.99	Acquired	81918	Direct
2010-02-25	Common	F	6986	$7.99	Disposed	74932	Direct

Footnotes

F1: This transaction reports the acquisition, effective February 25, 2010, of 20,525 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 246,303 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.