74HC257 pdf datasheet

MM54HC257/MM74HC257
Quad 2-Channel TRI-STATEÉ Multiplexer
General Description
This QUAD 2-TO-1 line data selector/multiplexer utilizes advanced
silicon-gate CMOS technology. Along with the high
noise immunity and low power dissipation of standard
CMOS integrated circuits, it possesses the ability to drive up
to 15 LS-TTL loads. The large output drive capability coupled
with the TRI-STATE feature make this device ideal for
interfacing with bus lines in a bus organized system. When
the OUTPUT CONTROL input line is taken high, the outputs
of all four multiplexers are sent into a high impedance state.
When the OUTPUT CONTROL line is low, the SELECT input
chooses whether the A or B input is used.
The 54HC/74HC logic family is speed, function, and pin-out
compatible with the standard 54LS/74LS logic family. All
inputs are protected from damage due to static discharge by
internal diode clamps to VCC and ground.
Features
Y Typical propagation delay: 12 ns
Y Wide power supply range: 2V±6V
Y Low quiescent current: 80 mA maximum (74HC Series)
Y TRI-STATE outputs for connection to system buses.