IN74AC138 Datasheet, PDF (1/5 Pages) Integral Corp. – 1-OF-8 DECODER/DEMULTIPLEXER High-Speed Silicon-Gate CMOS

IN74AC138
1-OF-8 DECODER/DEMULTIPLEXER
High-Speed Silicon-Gate CMOS
The IN74AC138 is identical in pinout to the LS/ALS138,
HC/HCT138. The device inputs are compatible with standard
CMOS outputs; with pullup resistors, they are compatible with
LS/ALS outputs.
The IN74AC138 decodes a three-bit Address to one-of-eight
active-low outputs. This device features three Chip Select
inputs, two active-low and one active-high to facilitate the
demultiplexing, cascading, and chip-selecting functions. The
demultiplexing function is accomplished by using the Address
inputs to select the desired device output; one of the Chip
Selects is used as a data input while the other Chip Selects are
held in their active states.
• 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
• Outputs Source/Sink 24 mA
ORDERING INFORMATION
IN74AC138N Plastic
IN74AC138D SOIC
T_A = -40° to 85° C for all
packages
PIN ASSIGNMENT
LOGIC DIAGRAM
PIN 16 =V_CC
PIN 8 = GND
FUNCTION TABLE
Inputs
Outputs
CS1CS2CS3 A2 A1A0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7
XXH
XXX H H H H H H H H
XHX
XXX H H H H H H H H
LXX
XXX H H H HHHHH
HLL
LLL L H H H H H H H
HLL
LLH H L H H H H H H
HLL
LHL H H L H H H H H
HLL
LHH H H H LHHHH
HLL
HLL H H H H L H H H
HLL
HLH H H H H H L H H
HLL
HHL H H H H H H L H
HLL
HHH H H H HHHHL
H = high level (steady state)
L = low level (steady state)
X = don’t care
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