ON SEMICONDUCTOR CORP — Director's Dealing 2011

May 10, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ON SEMICONDUCTOR CORP (ONNN)
CIK: 0001097864
Period of Report: 2011-05-06

Reporting Person: Schromm William A. (SVP & GM, Comp & Cnsmr Prd Grp)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-05-06	Common	A	22034.0000	$11.2400	Acquired	118663.8900	Direct
2011-05-06	Common	F	6768.0000	$11.2400	Disposed	111895.8900	Direct

Footnotes

F1: This transaction reports the acquisition, effective May 6, 2011 of 22,034 shares of common stock resulting from the attainment of a performance goal under an earlier award of Performance Based Restricted Stock Units ("PBRSU Award") as described in further detail below. The Compensation Committee of the Issuer originally awarded 264,414 PBRSUs to the Reporting Person with an effective grant date of March 2, 2009 subject to the Issuer's 2000 Stock Incentive Plan and a related award agreement. The PBRSU Award vests 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 6, 2011 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.