The IN74HC623 is identical in pinout to the LS/ALS623. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are compatible with LS/ALSTTL outputs.
The IN74HC623 is a 3-state noninverting transceiver that is used for 2-way communication between data buses. Two separate enables are available. The enable for bus A to B is active-high, the enable for bus B to A is active-low.

• 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