74AC138 Fairchild Semiconductor, 74AC138 Datasheet - Page 2

• Manufacturer Part Number: 74AC138
• Description: 1-of-8 Decoder/Demultiplexer
• Manufacturer: Fairchild Semiconductor

74AC138
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INPUT AND OUTPUT EQUIVALENT CIRCUIT
TRUTH TABLE
X: Don’t Care
LOGIC DIAGRAM
This logic diagram has not be used to estimate propagation delays
G 2B
X
X
H
L
L
L
L
L
L
L
L
ENABL E
G2A
X
H
X
L
L
L
L
L
L
L
L
G1
H
H
H
H
H
H
H
H
X
X
L
INPUTS
C
X
X
X
H
H
H
H
L
L
L
L
SEL ECT
B
H
H
H
H
X
X
X
L
L
L
L
A
H
H
H
H
X
X
X
L
L
L
L
Y0
H
H
H
H
H
H
H
H
H
H
L
PIN DESCRIPTION
Y1
H
H
H
H
H
H
H
H
H
H
L
15, 14, 13,
12, 11, 10,
PIN No
1, 2, 3
4, 5
9, 7
16
6
8
Y2
H
H
H
H
H
H
H
H
H
H
L
SYMBOL
G2A, G2B
Y0 to Y7
A, B, C
OUTPUTS
Y3
H
H
H
H
H
H
H
H
H
H
L
GND
V
G1
CC
Y4
H
H
H
H
H
H
H
H
H
H
L
Address Inputs
Enable Inputs
Enable Input
Outputs
Ground (0V)
Positive Supply Voltage
NAME AND F UNCTIO N
Y5
H
H
H
H
H
H
H
H
H
H
L
Y6
H
H
H
H
H
H
H
H
H
H
L
Y7
H
H
H
H
H
H
H
H
H
H
L