These devices are designed to multiplex signals from 4-bit data sources to 4-output data lines in bus-organized systems. The 3-state outputs do not load the data lines when the output-enable (G\) input is at a high logic level.
To ensure the high-impedance state during power up or power down, (G\) should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
Wide Operating Voltage Range of 2 V to 6 V
High-Current Inverting Outputs Drive up to 15 LSTTL Loads
Low Power Consumption, 80-µA Max ICC
’HC257 ...Typical tpd = 9 ns
’HC258 ...Typical tpd = 12 ns
±6-mA Output Drive at 5 V
Low Input Current of 1 µA Max
Provides Bus Interface from Multiple Sources in High-Performance Systems