DESCRIPTION
The 74HC643 is an advanced high-speed CMOS OCTAL BUS TRANSCEIVER (3-STATE) fabricated with silicon gate C2MOS technology.
This IC is intended for two-way asynchronous communication between data buses, and the direction of data transmission is determined by DIR input. The enable input G can be used to disable the device so that the buses are effectively isolated.
All inputs are equipped with protection circuits against static discharge and transient excess voltage.

■ HIGH SPEED:
   tPD = 10ns (TYP.) at VCC = 6V
■ LOW POWER DISSIPATION:
   ICC = 4µA(MAX.) at TA=25°C
■ HIGH NOISE IMMUNITY:
   VNIH = VNIL = 28 % VCC (MIN.)
■ SYMMETRICAL OUTPUT IMPEDANCE:
   |IOH| = IOL = 6mA (MIN)
■ BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL
■ WIDE OPERATING VOLTAGE RANGE:
   VCC (OPR) = 2V to 6V
■ PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 643