SL74HC253 Overview
SL74HC253 Dual 4-Input Data Selector/Multiplexer with 3-State Otputs High-Performance Silicon-Gate CMOS The SL74HC253 is identical in pinout to the LS/ALS253. The device inputs are patible with standard CMOS outputs; with pullup resistors, they are patible with LS/ALSTTL outputs.