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OSC
BUFF
OSC
RF
FM SD
BAND-W
AM SD
ADT
AM AGC
VT
++
+
-
+
+
+
+
+
L.P.F. L.P.F.
MUTE
L
35
R
AM-STEREO
LR-INPUT
DECODER
ANT 1-BIRDIE
STEREC
SW
P-DET
O
VCO
304KHzFF38KFF38K ¥Ł
FF
19K 2¥Ł
PILOT
DET
L-OUT R-OUT
30
29
28
27
26
25
24
23 22
21
20 19
18
17 16
REG
AGC
S-CURVE
DET
AMIF
AMIF
FM IN
(10.7MHZ)
GND V
CC
VCC
ALC
RUFF
AM
OSC
AM
MIX
AM
RF AMP
SD
COMP
AM
S-METER
FM
S-METER
AM FM
IF-BUFF
TUNING
DRIVE
STEREO
DRIVE
FM
DET
1
2
34
56 78
9101112 13 14 15
MONO
ST
FM
AM
MUTE
FM IFT
TU-LED
ST-LED
AM-IF
AMNARROW
SD
AMVSM
AMVSM
(SD-ADJ)
AM/FM
IF-BUFF
INTERNAL BLOCK DIAGRAM OF ICs
REFERENCE
DIVIDER
PHASE DETECTOR
CHARGE PUMP
UNIVERSAL
COUNTER
IFIN
AOUT
AIN
PD
UNLOCK
DETECTOR
SWALLOW COUNTER
1/16 1/17 4bits
12bits PROGRAMMABLE
DIVIDER
DATA SHIFT REGISTER
LATCH
1
2
POWER
ON
RESET
C B
I/F
XIN
XOUT
FMIN
AMIN
CE
DI
CL
DO
VDD
VSS
B01
B02 B03 B04 I01 I02
IC201 LA1837
IC202 LC72131
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IC401 TDA7440D
L-IN1
4
5
6
7
3
2
1
28
100K
100K
100K
100K
100K
100K
100K
100K
L-IN2
L-IN3
L-IN4
R-IN1
R-IN2
R-IN3
R-IN4
G
G
0/30dB
2dB STEP
INPUT MULTIPLEXER
+GAIN
MUXOUTL
INL
TREBLE(L) BIN(L) BOUT(L)
R
B
8 9 18 14 15
27
21
22
20
26
24
25
VOLUME TREBLE
I CBUS DECODER + LATCHES
BASS LOUT
SCL
SDA
DIG_GND
ROUT
CREFBOUT(R)BIN(R)TREBLE(R)INRMUXOUTR
V
S
AGND
SPKR ATT
LEFT
VOLUME TREBLE BASS
SUPPLY
SPKR ATT
RIGHT
10 11 19 12 13 23
R
B
2
VREF
D98AU883
28
1 2 3 4 5 6 7 8 9 10 11 12 13 14
27 26 25 24 23 22 21 20 19 18 17 16 15
BUY
BUY
BUY
10K
10K
10K
10K
10K
50K
50K
100K
LEVEL
SHIFT
T S D
REGULATOR
MUTE
LEVEL
SHIFT
LEVEL
SHIFT
LEVEL
SHIFT
IC803 KA9258D
PIN Description
Pin No. Symbol I/O Description
1 DO1.1 O DRIVE OUTPUT
2 DO1.1 O DRIVE OUTPUT
3 DI1.1 I DRIVE INPUT
4 DI1.1 I DRIVE INPUT
5 REG REGULATOR
6 REO O REGULATOR OUTPUT
7 MUTE MUTE
8 GND1 GROUND
9 DI2.1 I DRIVE INPUT
10 DI2.2 I DRIVE INPUT
11 DO2.1 O DRIVE OUTPUT
12 DO2.2 O DRIVE OUTPUT
13 GND2 GROUND
14 OPOUT O OPAMP OUTPUT
Pin No. Symbol I/O Description
15 OPIN (-) I OPAMP OUTPUT(-)
16 OPIN (+) I OPAMP INPUT(+)
17 DO3.1 O DRIVE OUTPUT
18 DO3.2 O DRIVE OUTPUT
19 DI3.1 I DRIVE INPUT
20 DI3.2 I DRIVE INPUT
21 VCC1 SUPPLY VOLTAGE
22 VCC2 SUPPLY VOLTAGE
23 VREF 2.5V BIAS VOLTAGE
24 DI4.1 I DRIVE INPUT
25 DI4.2 I DRIVE INPUT
26 DO4.1 O DRIVE OUTPUT
27 DO4.2 O DRIVE OUTPUT
28 GND3 GROUND
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