ON SEMICONDUCTOR CORP — Director's Dealing 2012

May 7, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ON SEMICONDUCTOR CORP (ONNN)
CIK: 0001097864
Period of Report: 2012-05-03

Reporting Person: JACKSON KEITH D (Director, CEO & Pres.)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-05-03	Common	A	140550.0000	$8.3900	Acquired	1574225.0000	Direct
2012-05-03	Common	F	58400.0000	$8.3900	Disposed	1515825.0000	Direct

Footnotes

F1: This transaction reports the acquisition, effective May 3, 2012, of 140,550 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 1,686,609 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, which vested generally over a three-year (twelve quarter) period 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, is now fully vested.

F2: This disposition transaction represents shares withheld by the Issuer pursuant to the Reporting Person's March 2, 2009 PBRSU award. On May 3, 2012, 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.