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IC BLOCK DIAGRAM & DESCRIPTION
IC231 LA1844ML (Audio Tuner)
FM
IF
FM
DET
LEVEL
DET
S-CURVE
AM/FM
IF
BUFF
REG
GND
COMP
TUNING
DRIVE
AM
IF
AM
DET
VCC
AGC
PILOT
CANCEL
PILOT
DET
DECODER
ANTI-BIRDIE
STEREO
SW
FF
38k
FF
19k
VCO
304kHz
AM
RF.AMP
AM
MIX
AM
OSC
ALC
BUFF
P-DET
FF
19k
2
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
IC400,421,423 KIA4558F(Operation Amp.)
4
3
2
1
5
6
7
8
+IN B
-IN B
OUT B
V
CC
V
EE
+IN A
-IN A
OUT A
+
-
+
-
A
B
IC420,424 NJM2058(Operation Amp.)
1
2
3
4
11
12
13
14
A OUTPUT
A +INPUT
V+
C+INPUT
A INPUT
B INPUT
D+INPUT
V
D INPUT
D OUTPUT
A
D
5
6
7
8
9
10
B+INPUT
B OUTPUT
C INPUT
C OUTPUT
B
C
IC241 LC7212M-D(PLL)
2
1
24
17
16
3
4
5
6
18
15
7
8
9
10
11
14
19
20
21
22
13
Vssx
XIN
XOUT
FMIN
AMIN
CE
DI
CL
DO
V
DD
Vssd
PD
AIN
AOUT
Vssa
IFIN
IO1 IO2
BO1 BO2 BO3 BO4
PHASE DETECTOR
CHARGE PUMP
UNLOCK
DETECTOR
UNIVERSAL
COUNTER
REFERENCE
DIVIDER
SWALLOW COUNTER
1/16, 1/17 4bits
12bits PROGRAMMABLE
DIVIDER
DATA SHIFT REGISTER LATCH
1/2
CCB
I / F
POWER
ON
RESET