SL74HC257

System Logic

Semiconductor

SLS

Quad 2-Input Data Selector/Multiplexer

with 3-State Outputs

High-Performance Silicon-Gate CMOS

The SL74HC257 is identical in pinout to the LS/ALS257. The device

inputs are compatible with standard CMOS outputs; with pullup

resistors, they are compatible with LS/ALSTTL outputs.

This device selects a (4-bit) nibble from either the A or B inputs as

determined by the Select input. The nibble is presented at the outputs

in noninverted from when the Output Enable pin is at a low level. A

high level on the Output Enable pin switches the outputs into the high-

impedance state.

• Outputs Directly Interface to CMOS, NMOS, and TTL

• Operating Voltage Range: 2.0 to 6.0 V

• Low Input Current: 1.0 µA

• High Noise Immunity Characteristic of CMOS Devices

ORDERING INFORMATION

SL74HC257N Plastic

SL74HC257D SOIC

° to 125° C for all packages

FUNCTION TABLE

Inputs

Outputs

Output

Enable

Select

Y0-Y3

H

X

Z

L

L

A0-A3

L

H

B0-B3

X=don’t care

Z = high-impedance state

A0-A3,B0-B3=the levels of the respective

Nibble Inputs

LOGIC DIAGRAM

PIN 8 = GND

PIN ASSIGNMENT