ON SEMICONDUCTOR CORP — Director's Dealing 2010

May 7, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ON SEMICONDUCTOR CORP (ONNN)
CIK: 0001097864
Period of Report: 2010-05-05

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-05-05	Common	A	31519	$7.75	Acquired	98565	Direct
2010-05-05	Common	F	9938	$7.75	Disposed	88627	Direct

Footnotes

F1: This transaction reports the acquisition, effective May 5, 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: This disposition transaction represents shares withheld by the Issuer pursuant to the Reporting Person's March 2, 2009 award of Performance Based Restricted Stock Units ("PBRSUs"). On May 5, 2010, certain of these units vested. These shares were withheld to satisfy the Reporting Person's withholding obligations for various taxes and similar items. The Issuer will pay these taxes on behalf of the Reporting Person.