Circuit Description
9.
Figure 9-3 Stereo audio signal processing
9.2.2
Mono
In mono sets, the signal goes via the SAW filter (position 1002/
1003), to the audio demodulator part of the UOC IC 7200. The
audio output on pin 48 goes to the audio amplifier (AN7523 at
position 7902).
The volume level is controlled at this IC (pin 9) by a
'VolumeMute' control line from the microprocessor.
The audio signal from IC 7902 is then send to the speaker and
headphone output panel.
Figure 9-4 Mono audio signal processing
TUNER
VBAT
AUDIO
12V
3.9V
3.3V
FM IF
BUFFER
NOT FOR
NAFTA
VIDEO SOURCE
SELECTION
RF ANT.
FM ANT.
EXT. AUDIO
INPUT
7801
AUDIO SOURCE SELECTION
CONTROL
EXT. AUDIO OUT
7861
7831
7834
7835
7209
7210
7901
10
1000
0265
11
1
1
1
AGC
1200 : 1202
18
19
38
INT_CVBS
EXT_CVBS
40
42
16
17
15
30
68
I2C
50:53
EXT RGB/YUV INPUT
56:58
7330
EHT
7460
H
EW
V+
V-
7471
7602
7200
POWER
SUPPLY
CL 16532016_01a.eps
120401
AUDIO
AMPL.
SAW
FILTER
SOUND
IF
DEMOD.
AUDIO DECODING
AND
PROCESSING
SELECTION
MATR. SWITCH
VISION
IF
DEMOD.
NVM
VIDEO
AMPL.
HOR.
DEFL.
+
EW
VERT.
DEFL.
µ
P
VIDEO
PROCESSING
RGB/YUV
PROCESSING
SYNC
PROCESSING
SOUND
TRAP
VIDEO
SWITCH
EXT. VIDEO
INPUT
7802
TUNER
RF ANT.
EXT. AUDIO
OUTPUT
EXT. AUDIO
INPUT
7902
10
1000
11
1
1
1
AGC
18
19
68
7602
AUDIO SWITCH
7200
AVL
FM PRE
AMP.
NOT FOR
NAFTA
AUDIO
AMPL.
SMART
SND
SAW
FILTER
SOUND
IF
DEMOD.
VISION
IF
DEMOD.
NVM
µ
P
CL 16532016_01b.eps
120401
FM ANT.
0265
www.freeservicemanuals.info
22/11/2016
Published in Heiloo Holland
