Sanyo LCD-22XR9DZ, Service Manual

Page: 15 / 43

Working principle analysis of the unit
1
、
PAL/SECAM signal flow
PAL/SECAM signal from antenna is inputted into TUNER
FQD1116
which is
an analog-digital-integrative model, the analog RF signal is demodulated by the
TUNER, then
CVBS
signal and audio difference IF signal are outputted. TUNER
FQD1116
is controlled by main chip
MSD209
（
with
embedded
CPU
）
through
I2C
TV CVBS
signal is inputted into main chip
MSD209
directly to be processed
by modules “
VIDEO DECODER
、
DEINTERLACE
and
SCALER
”, then
LVDS
signal is outputted to drive LCD panel.
SIF
audio signal is inputted into main chip
MSD209
directly and processed
by modules of demodulation, pre-amplification, acoustic effect processing and
volume control, then the audio signal are inputted into left and right earphone
amplifiers
BH3547F
to be amplified and then be divided to two signals, one is
outputted to earphone jack, the other is inputted into audio power amplifier
TDA7266SA
(
AB
type) to be amplified and then be outputted to speakers.
2
、
DVB-T
signal flow
DVB-T
signal from antenna is inputted into TUNER
FQD1116
to be
tuned,
HF
amplified, IF amplified and
SAW FILTER inside,
then
IF
signal is outputted to
demodulating chip
CE6353
to be demodulated and then be inputted into main
chip
MSD209
with format of standard serial or parallel
TS
stream for de-double-
using and decoding.
Video route: de-double-using video signal is decoded by main chip
MSD209
and then digital
vi
d
e
o signal is outputted, in the end
LVDS
signal is outputted to
drive
LCD
panel after a series of digital processes and
OSD
addition within main
chip
MSD209
.
Audio route: de-double-using audio signal is decoded into
Dolby AC-3
signal or
MPEG
multi-sound-track digital audio signal by inner decoder of main
chip
MSD209
, then one is outputted through
SPDIF
directly; after the process of
“sub-transform and
DAC
”, the other is outputted as analog audio signal with
double-sound-track (
stereo
), the analog audio signal is inputted into the rear part
of main chip
MSD209
for acoustic process and volume control, then inputted into
left and right sound tracks of earphone amplifier
BH3547F
respectively to be
amplified, now the audio signal is divided into two, one is outputted to earphone
jack directly, the other is inputted into audio power amplifier
TDA7266SA
(
AB
type) to be amplified and then outputted to speakers.
3
、
AV
signal flow
AV
video signal is inputted into main chip
MSD209
directly and processed
by modules of “
VIDEO DECODER
、
DEINTERLACE and SCALER
”, then
LVDS
signal is outputted to drive
LCD
panel.
AV
audio signal is processed by circuits of “voltage divided, impedance
matching and alternating-current coupling”, then inputted into main chip
MSD209
directly for acoustic process and volume control, now the audio signal is divided
into two, one is outputted to earphone jack directly, the other is inputted into
audio power amplifier
TDA7266SA
(
AB
type) to be amplified and then outputted
to speakers.
bus.