TECHNICAL DATA
IN74HC139A
Dual 1-of-4 Decoder/Demultiplexer
The IN74HC139A is identical in pinout to the LS/ALS139. The
device inputs are compatible with standard CMOS outputs; with pullup
resistors, they are compatible with LS/ALSTTL outputs.
This device consists of two independent 1-of-4 decoders, each of
which decodes a two-bit Address to one-of-four active-low outputs.
Active-low Selects are provided to facilitate the demultiplexing and
cascading functions. The demultiplexing function is accomplished by
using the Address inputs to select the desired device output, and utilizing
the Select as a data input.
ORDERING INFORMATION
IN74HC139AN Plastic
IN74HC139AD SOIC
TA = -55° to 125° C for all packages
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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
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
Inputs
Outputs
Select
H
A1
X
L
A0 Y0 Y1
Y2
H
H
H
L
Y3
H
H
H
H
L
PIN 16 =VCC
PIN 8 = GND
X
L
H
L
H
H
L
L
L
L
H
L
H
H
H
L
H
H
H
H
L
H
H
X = don’t care
Rev. 00