JVC CA-PCX290, Service Manual

Page: 79 / 83

1.Terminal layout 2.Block diagram
TC9422F(IC401):System Electronic Volume
1.Terminal layout 2.Block diagram
3.Pin function
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Pin No. Symbol I/O Function
1 GND - Ground pin
2 L-IN1 I Audio signal input pins
3 L-IN2 I Audio signal input pins
4 L-IN3 I Audio signal input pins
5 L-IN4 I Audio signal input pins
6 L-SW-OUT I Audio signal input pins
7 L-VR-IN I Main volume input pins
8 L-B1 - Tone control tap pin 1 for bus
9 L-B2 - Tone control tap Pin 2 for bus
10 L-B3 - Tone control tap pin 3 for bus
11 L-Tone-OUT O Tone control output pins
12 L-T1 - Tone control tap pin for treble
13 Vref I Reference voltage input pin
14 CK I Clock input pin
15 DATA I Data input pin
16 STB I Strobe input pin
17 R-T1 - Tone control tap pin for treble
18 R-Tone-OUT O Tone control output pins
19 R-B3 - Tone control tap pin 3 for bus
20 R-B2 - Tone control tap Pin 2 for bus
21 R-B1 - Tone control tap pin 1 for bus
22 R-VR-IN I Main volume input pins
23 R-SW-OUT I Audio signal input pins
24 R-IN4 I Audio signal input pins
25 R-IN3 I Audio signal input pins
26 R-IN2 I Audio signal input pins
27 R-IN1 I Audio signal input pins
28 V
DD
- Power supply voltage pin
PCX290
57
28 1
16 13 14 15
5
6
3
4
2
24
23
22
21
20
19
18
17
26
25
27
LATCH
+
DECODER
CIRCUIT
32BIT SR
7
8
9
10
11
12
GND VDD
L-IN1
L-IN2
L-IN3
L-IN4
L-VR-IN
L-B1
L-B2
L-B3
L-Tone-OUT
L-T1
Vref CK DATA STB
R-T1
R-Tone-OUT
R-B3
R-B2
R-B1
R-VR-IN
R-SW-OUT
R-IN4
R-IN3
R-IN2
R-IN1
INPUT SELECTOR
100k W
100k W
MAIN VR
50k W /64STEP
50k W
BASS VR
50k W /16STEP
TREBLE VR
50k W /16STEP
750 W
500 W
13k W
INPUT SELECTOR
+ -
GAIN CONTROL
0,6,12,18dB
+ -
+ -
- +
-
+
BASS VR
50k W /
16STEP
TREBLE VR
50k W /
16STEP
13k W 500 W
750 W
50k W
CAPACITOR FOR
OSCILLATION
CAPACITOR FOR
OSCILLATION
MAIN VR
50k W /64STEP
GAIN CONTROL
0,6,12,18dB
L-SW-OUT
50k W 50k W
+ -
+ -
- +
- +
1k
W
1k
W
13kW
13k
W
INPUT SELECTOR
GAIN CONTROL
MAIN VR
CAPACITOR FOR
BASS VR
TREBLE VR
32BIT SR
32BIT SR
TREBLE VR
BASS VR
CAPACITOR FOR
MAIN VR
GAIN CONTROL
INPUT SELECTOR