The HCT257 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 (OE)\ input is at the high logic level.
To ensure the high-impedance state during power up or power down, OE\ 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.
Operating Voltage Range of 4.5 V to 5.5 V
High-Current 3-State Outputs Interface Directly With System Bus
Typical tpd = 17 ns
Low Power Consumption, 80-µA Max ICC
±6-mA Output Drive at 5 V
Low Input Current of 1 µA Max
Inputs Are TTL-Voltage Compatible
Provide Bus Interface From Multiple Sources in High-Performance Systems
