Description Of Major Ics - JVC MX-GT90 Service Manual

Description of major ICs

AN7345(IC302) : PB/REC amp.
1. Block diagram
L1
L2
24
23
2
1
R2
R1
2. Pin Function
Pin
Symbol
I/O
No.
I
1 Playback amplifier input
R1
2
R2 Playback amplifier input
I
3 NF2 I Playback amplifier negative feedback
4 O
OUT2 Playback amplifier output
Equalizer
5 EQ2 I
CTL2 I Pre Amplifier input switching time
6
constant
RIN2 I
Recording amplifier input
7
8 RNF2 I Recording amplifier negative feedback
9 ROUT2 O Recording amplifier output
ALC low cut
LC I
10
I ALC low pass filter
11
LPF
GND I
12
NF1
OUT1 EQ1 CTL1 RIN1
22
21 20
19
Pre
Pre
Source
AMP
CTRL
EQ
Pre
CTRL
AMP
3 4 5
6
EQ2 CTL2
OUT2 RIN2
NF2
Function
EQ
RNF1 ROUT1 CTL
RF
18 16 15 14
17
ALC
AMP
ALC
ALC
AMP
7 8
9 10 11
LC
RNF2 LPF
ROUT2
Pin
Symbol
No.
13
Vcc
14
RF
EQCTL
15
16
ROUT1
17 RNF1
18 RIN1
CTL1
19
20
EQ1
21
OUT1
NF1
22
L2
23
24
L1
VCC
13
REPPLE
REJ
12
GND
I/O
Function
I
Power supply
I
Ripple filter
I
EQ control
O
Recording amplifier output
Recording amplifier negative feedback
I
I Recording amplifier input
Pre amplifier input switching control
I
I
Equalizer
O Playback amplifier output
I Playback amplifier negative feedback
Playback amplifier input
I
Playback amplifier input
I
MX-GT90
1-31