Copyright©2007 LG Electronics. Inc. All right reserved.
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LGE Internal Use Only
Only for training and service purposes
3. Analog RF(NTSC) Video signal flow chart
*Tuner(NTSC) Video signal flowchart
RF Signal Input
(NTSC)
LCD Panel
CVBS
CVBS
for Caption
I
2
C Comm.
TU_CVBS
LVDS Signal
IC105
TUNER
IC706
Analog MUX
(Video switch)
IC401
DTV Controller
IC107
SD Video Filter
IC705
Micro Processor
P503
LVDS Connector
The analog RF signal(NTSC) received in the input terminal of the tuner is converted to the base band signal in the
tuner(IC105) to send out the composite signal.
This CVBS signal is received by IC706 which is the analog video switch. The analog video switch receives the
CVBS signal sent from the tuner and the external signal, AV1, AV2, AV3, S-Video caption and Component caption
signal and sends out one of the signals.
The external input mode selected by the TV/AV button on the remote controller is the video signal selected for output.
The output signal is the decoded in the DTV controller of IC401 and converted to LVDS signal to be sent to the
LCD panel through the LVDS connector of P503.
Also the output signal from the analog video switch of IC706 is used as the caption signal.
This signal is amplified 2 times to send to the microprocessor(IC705), and IC705 arranges the caption signal to send
the caption information to the DTV controller through the I
2
C communications line.