JVC MX-G950V Service Manual page 50

MX-G950V/MX-G880V
MX-G850V/MX-G750V
TDA7439 (IC303) : Control volume
1.Pin layout
SDA
1
CRE
2
Vs
3
AGND
4
ROUT
5
LOUT 6
R-IN4 7
R-IN3 8
R-IN2
9
R-IN1
10
L-IN1
11
L-IN2
12
L-IN3
13
L-IN4
14
MUXOUTL TDA7439
15
2.Block diagram
L-IN1
11
G
L-IN2
12
L-IN3
13
0/30dB
L-IN4 14
2dB STEP
R-IN1 10
R-IN2 9
G
R-IN3 8
R-IN4
7
INPUT
MULTIPLEXER
GAIN
TC7W08FU-X (IC107) : Nand gate
1. Pin layout & Block diagram
1A 1
1B
2
2Y 3
GND
4
1-50
CSL
30
DIG GND
29
TREBLE(R)
28
TREBLE(L)
27
MIN(L)
26
MOUT(L)
25
BOUT(L)
24
BIN(L)
23
BOUT(R)
22
BIN(R)
21
MOUT(R)
20
19 MIN(R)
18 INR
17 MUXOUTR
16 INL
15 16 27
TREBLE
VOLUME
2
I C BUS DECODER LATCHES
VOLUME
TREBLE
17 18 28
2. Truth table
8 Vcc
1Y
7
6 2B
2A
5
25 23
26 24
MIDLE
BASS
MIDLE
BASS
21 22
19 20
A B Y
L L L
L H L
H L L
H H H
SPEAKER
LOUT
6
ATT
LEFT
30
SCL
1
SDA
29 DIG-GND
SPEAKER
5
ROUT
ATT
RIGHT
3
Vs
SUPPLY
4
AGND
2