On Semiconductor acquired Fairchild Semiconductor in 2017, as per their statement below.
ON Semiconductor completed the Integration of Fairchild Semiconductor Business Systems and Processes
Changes became effective on Monday, October 30, 2017
CHANGE DETAILSON Semiconductor acquired Fairchild Semiconductor in September of 2016. We have been working diligently over the past year to complete the integration of Fairchild Semiconductor products into the ON Semiconductor order and fulfillment processes. The integration was completed on Monday October 30th, 2017
Check out their press release here.