Description Of Major Ics ----------------- - JVC XV-S300BK Service Manual

Description of major ICs
74VHC00MTC-X (IC455,IC503) : 2-input nand gate
1.Pin layout
1A 1
1B 2
1Y 3
2A 4
2B 5
2Y 6
GND 7
(TOP VIEW)
74VHC74MTC-X (IC454) : ZIVA Wait
1.Terminal layout
1
CLR1
2
D1
CK1 D1
3
CK1
PR1CLR1
4
Q1 Q1
PR1
5
Q1
6
D2 CK2
Q1
PR2CLR2
7
GND
Q2 Q2
3.Pin function
Symbol I/O
Pin No.
1 CLR1 I
2 D1 I
3 CK1 I
4 PR1 I
5 Q1 O
6 Q1 O
7 GND -
14 VCC
13 4A
12 4B
11 4Y
10 3A
9 3B
8 3Y
2.Trouth table
14
Vcc
13
CLR2 CLR PR
12
D2 L H
11
CK2
H
10
PR2
L
9
Q2
H H
8
Q2
H H
H H
Description
Direct clear input 1
Data input 1
Clock pulse input 1
Direct preset input 1
Output
Output
Connect to ground
2.Truth table
A B
L L
L H
H L
H H
L : High impedance
Input
D CK Q
X X L
L X X H
L X X H(Note 1)
L L
H H
X Qn
Symbol I/O
Pin No.
8 Q2 O Output
9 Q2 O Output
10 PR2 I Direct preset input 2
11 CK2 I Click pulse input 2
12 D2 I Data input 2
13 CLR2 I Clock clear input 2
14 VCC - Power supply
XV-S300BK/XV-S302SL
Y
H
H
H
L
Output
Function
Q
H Clear
L Preset
H(Note 1)
H
L
Qn No change
Description
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