TECHNICAL DATA
IN74AC257
Quad 2-Input Data Selector/Multiplexer
with 3-State Outputs
High-Speed Silicon-Gate CMOS
The IN74AC257 is identical in pinout to the LS/ALS257,
HC/HCT257. The device inputs are compatible with standard CMOS
outputs; with pullup resistors, they are compatible with LS/ALS 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;
0.1
μA
@ 25°C
•
High Noise Immunity Characteristic of CMOS Devices
•
Output Source/Sink 24 mA
ORDERING INFORMATION
IN74AC257N Plastic
IN74AC257D SOIC
T
A
= -40° to 85° C for all packages
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
Inputs
Output
Enable
H
L
L
PIN 16 =V
CC
PIN 8 = GND
Select
X
L
H
Outputs
Y0-Y3
Z
A0-A3
B0-B3
X=don’t care
Z = high-impedance state
A0-A3,B0-B3=the levels of the respective
Nibble Inputs
Rev. 00
IKSEMICON [ IK SEMICON CO., LTD ]
