The IN74HC27A is high-speed Si-gate CMOS device and are pin compatible with low power Schottky TTL (LSTTL) . The device provide Triple 3-input NOR function. • Outputs Directly Interface to CMOS, NMOS, and TTL. • Operating Voltage Range: 2.0 to 6.0 V. • Low Input Current: 1.0 µA. • High Noise Immunity Characteristic of CMOS Devices.