Datasheet

2
Functional Diagram
‘HC243, ‘HCT243
TRUTH TABLE
CONTROL INPUTS
HC, HCT243 SERIES
DATA PORT STATUS
OEB OEA An Bn
HHO I
LHZZ
HLZZ
LLIO
H= High Voltage Level
L= Low Voltage Level
I= Input
O= Output (Same Level as Input)
Z= High Impedance
To prevent excess currents in the High Z modes all I/O terminals should be terminated with 10kΩ
to 1MΩ resistors.
DIRECTION
SELECT LOGIC
A0
A1
A2
A3
OEB
OEA
3
4
5
6
1
13
11
10
9
8
B0
B1
B2
B3
CD54HC243, CD74HC243, CD54HCT243, CD74HCT243