JVC AX-M9000 Service Manual page 18

AX-M9000
TC74HC373HF-X(IC522, IC523, IC524) : Shift register for relay control
1. Pin layout
OE 1
Q0 2
3
D0
D1 4
Q1 5
Q2 6
D2
7
D3
8
Q3 9
GND
10
(TOP VIEW)
3. Block diagram
D0
3
LE
OE
1-18
20 Vcc
19
Q7
18
D7
17 D6
16
Q6
15
Q5
14 D5
13 D4
Q4
12
LE
11
D2
D1
4 7
D D D
Q
Q Q
L L L
2 5
Q1
Q0
2. Truth table
INPUTS
OE
H
L
L
L
X : Don't Care
Z : High impedance
Qn: The Q output level immediately
before the LE becomes to "L".
D5
D3 D4
8 13
14
D D D
Q Q
L L
6
9
12
Q3 Q4
Q2
OUTPUTS
LE D Q
X
X Z
L
Qn
X
H L L
H
H
H
D6
D7
18
17
D
D
Q Q
Q
L
L
L
16 19
15
Q6
Q5
Q7