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MC54HC138A Datasheet, PDF (1/7 Pages) Motorola, Inc – 1-OF-8 DECODER / DEMULTIPLEXER | |||
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MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
1-of-8 Decoder/Demultiplexer
HighâPerformance SiliconâGate CMOS
The MC54/74HC138A is identical in pinout to the LS138. The device
inputs are compatible with standard CMOS outputs; with pullup resistors,
they are compatible with LSTTL outputs.
The HC138A decodes a threeâbit Address to oneâofâeight activeâlow
outputs. This device features three Chip Select inputs, two activeâlow and
one activeâhigh to facilitate the demultiplexing, cascading, and chipâselect-
ing 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.
⢠Output Drive Capability: 10 LSTTL Loads
⢠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
⢠In Compliance with the Requirements Defined by JEDEC Standard
No. 7A
⢠Chip Complexity: 100 FETs or 29 Equivalent Gates
LOGIC DIAGRAM
ADDRESS
INPUTS
A0 1
A1 2
A2 3
15 Y0
14 Y1
13 Y2
12 Y3
11 Y4
10
Y5
9 Y6
7
Y7
ACTIVEâLOW
OUTPUTS
CS1 6
CHIPâ
4
SELECT CS2
INPUTS
CS3
5
PIN 16 = VCC
PIN 8 = GND
FUNCTION TABLE
Inputs
Outputs
CS1CS2 CS3 A2 A1 A0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7
X X H XXX HHH HHHH H
X H X XXX HHH HHHH H
L X X XXX HHH HHHH H
H L L LLL LHHHHHHH
H L L LLHH L HHHHHH
H L L LHL HH L HHHHH
H L L LHH H H H L H H H H
H L L HLL HHHH L HHH
H L L HLHHHHHH L HH
H L L HHL H H H H H H L H
H L L HHH H H H H H H H L
H = high level (steady state); L = low level (steady state);
X = donât care
10/95
© Motorola, Inc. 1995
1
MC54/74HC138A
16
1
J SUFFIX
CERAMIC PACKAGE
CASE 620â10
16
1
N SUFFIX
PLASTIC PACKAGE
CASE 648â08
16
1
D SUFFIX
SOIC PACKAGE
CASE 751Bâ05
16
1
DT SUFFIX
TSSOP PACKAGE
CASE 948Fâ01
ORDERING INFORMATION
MC54HCXXXAJ
MC74HCXXXAN
MC74HCXXXAD
MC74HCXXXADT
Ceramic
Plastic
SOIC
TSSOP
PIN ASSIGNMENT
A0 1
A1 2
A2 3
CS2 4
CS3 5
CS1 6
Y7 7
GND 8
16 VCC
15 Y0
14 Y1
13 Y2
12 Y3
11 Y4
10 Y5
9 Y6
REV 6
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