B to A B to A Output X L H L H H = HIGH Voltage Level L = LOW Voltage Level X = Immaterial FACT DATA DataSheet 4 U .com 5-1 www.DataSheet4U.com MC74AC640 MC74ACT640 MAXIMUM RATINGS* Symbol VCC Vin Vout Iin Iout ICC Tstg Parameter DC Supply Voltage (Referenced to GND) DC Input Voltage (Referen.