ON: Material agreement · Other company developments

Item 1.01 Entry into a Material Definitive Agreement. Amended and Restated Agreement and Plan of Merger As previously announced, on June 25, 2026, ON Semiconductor Corporation (“ onsemi ”), a Delaware corporation, Sonic Acquisition Corp., a Delaware corporation and a wholly owned subsidiary of onsemi (“ Merger Sub ”), and Synaptics Incorporated, a Delaware corporation (“ Synaptics ”), entered into an Agreement and Plan of Reorganization, providing for the acquisition of Synaptics by onsemi. On October 1, 2026 , onsemi, Synaptics and Merger Sub entered into an Amended and Restated Agreement and Plan of Merger (the “ Amended Merger Agreement ”). The Amended Merger Agreement amends and restates in its entirety the Agreement and Plan of Reorganization. Pursuant to the terms and subject to the conditions set forth in the Amended Merger Agreement, Merger Sub will merge with and into Synaptics (the “ Merger ”), with Synaptics surviving the Merger as a wholly owned subsidiary of onsemi. Capitalized terms used but not defined herein have the meanings set forth in the Amended Merger Agreement. The Amended Merger Agreement was entered into following Synaptics’ receipt of an unsolicited Acquisition Proposal from a third party, referred to as “Party A” in onsemi’s Registration Statement on Form S-4 filed with the Securities and Exchange Commission (the “ SEC ”) on August 21, 2026 (the “ Registration Statement ”). The boards of directors of each of onsemi and Synaptics have unanimously approved the Amended Merger Agreement, including the Merger and the other transactions contemplated thereby, and have each unanimously determined that the revised transaction provided in the Amended Merger Agreement is in the best interests of their company and its respective stockholders. Merger Consi