Adcom GTP-506 Service Manual page 21

IC BLOCK DIAGRAM
U901: LA1837
30 29
ALC
AM
OSC
BUFF
SD
COMP
FM
S-METER S-CURVE
FM
AM IF
DET
1 2
U903: LC7218
XIN
1
XOUT
24
FMIN
19
AMIN
18
CE
2
DI
3
CL
4
D0 5
28 27 26 25 24
REG
AM AM
MIX RF.AMP
AGC
AM IF DET
AM
S-METER
AM/FM
IF-BUFF
TUNING STEREO
DRIVE DRIVE
GND
3 4 5 6 7
REFERENCE
DIVIDER
1
SWALLOW COUNTER
2
1/16, 1/17 4 BIT
12-BIT PROGRAMMABLE
SHIFT REGISTER
LATCH
9 10 11
OUT0 OUT1 OUT2 OUT3 OUT4 OUT5 OUT6
23 22 21 20 19
3 rd 5 th
DECODER
ANTI-BIRIDE
P-DET
STEREO
Ø
SW
VCO
FF FF
304kHz 38k 19k
V
CC
8 9 10 11 12
SYC
6
PHASE DETECTOR
CHARGE PUMP
DIVIDER
UNIVERSAL
COUNTER
12 13 14 17 7
IN0
21
GTP-506
18 17 16
MUTE
FF PILOT
19k DET
13 14 15
21 PD1
PD2
22
HCTR
16
15 LCTR
20 V
DD
23 V
SS
8
IN1