74HC643 Octal transceiver; 3-state; true/inverting
74HC643D Octal bus transceiver; 3-state; true/inverting
74HC643D-T 8-Bit Inverting/Non-Inverting Bus Trasceiver
74HC643N Octal bus transceiver; 3-state; true/inverting
74HC643U Octal bus transceiver; 3-state; true/inverting