Datasheet

2
Functional Diagram
3 CIRCUITS IDENTICAL TO CIRCUIT
IN ABOVE DASHED ENCLOSURE
OE
S
4I
1
4I
0
3I
1
3I
0
2I
1
2I
0
1I
1
1I
0
15
1
13
14
10
11
6
5
3
2
12
9
7
4
P
N
4Y
3Y
2Y
1Y
TRUTH TABLE
OUTPUT
ENABLE
SELECT
INPUT DATA INPUTS OUTPUT
OE S I
0
I
1
Y
HXXXZ
LLLXL
LLHXH
LHXLL
LHXHH
H= High Voltage Level
L= Low Voltage Level
X= Don’t Care
Z= High Impedance, OFF State
CD54HC257, CD74HC257, CD54HCT257, CD74HCT257