IN74HCT138A Datasheet, PDF (1/5 Pages) Integral Corp. – 1-OF-8 DECODER/DEMULTIPLEXER

IN74HCT138A
1-OF-8 DECODER/DEMULTIPLEXER
High-Performance Silicon-Gate CMOS
The IN74HCT138A is identical in pinout to the LS/ALS138.
The IN74HCT138A may be used as a level converter for
interfacing TTL or NMOS outputs to High Speed CMOS inputs.
The IN74HCT138A decodes a three-bit Address to one-of-
eight active-lot 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.
• TTL/NMOS Compatible Input Levels
• Outputs Directly Interface to CMOS, NMOS, and TTL
• Operating Voltage Range: 4.5 to 5.5 V
• Low Input Current: 1.0 µA
ORDERING INFORMATION
IN74HCT138AN Plastic
IN74HCT138AD SOIC
T_A = -55° to 125° 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 HHHHH
XHX
XXX
H H H HHHHH
LXX
XXX
H H H HHHHH
HLL
LLL
L H H HHHHH
HLL
LLH
H L H HHHHH
HLL
LHL
H H L HHHHH
HLL
LHH
H H H LHHHH
HLL
HLL
H H H HLHHH
HLL
HLH
H H H HHLHH
HLL
HHL
H H H HHHLH
HLL
HHH
H H H HHHHL
H = high level (steady state)
L = low level (steady state)
X = don’t care
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