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M74HC243
INPUT AND OUTPUT EQUIVALENT CIRCUIT
LOGIC DIAGRAM
PIN DESCRIPTION
PIN No
1
2, 12
3, 4, 5, 6
11, 10, 9, 8
13
7
14
SYMBOL
GAB
NC
1A to 4A
1B to 4B
GBA
GND
VCC
NAME AND FUNCTION
Output Enable Input
(Active LOW)
Not Connected
Data Inputs/Outputs
Data Inputs/Outputs
Output Enable Input
Ground (0V)
Positive Supply Voltage
TRUTH TABLE
INPUTS
FUNCTION
GAB
H
L
H
L
GBA
H
L
L
H
A BUS B BUS
OUTPUT INPUT
INPUT OUTPUT
HIGH IMPEDANCE
HIGH IMPEDANCE
OUTPUTS
A=B
B=A
Z
Z
This logic diagram has not be used to estimate propagation delays
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