The 74AUP1Z125 is a high-performance, low-power, low-voltage, Si-gate CMOS device, superior to most advanced CMOS compatible TTL families. When not in use the EN input can be driven HIGH, pulling up the X1 input and putting the device in a low power disable mode. Schmitt-trigger action at the EN input makes the circuit tolerant to slower input rise and fall times across the entire VCC range from 0.8 V to 3.6 V.