- 5 -
This unit circuit consists of four sections, i.e., vertical serrated wave generator, vertical
geometric correction processor, horizontal (E-W) geometric correction processor, EHT
follow-up and over-voltage protection circuit, as detailed in Fig. 5.
5.
Filter CVBS/Y/C switching unit circuit
The filter CVBS/Y/C switching unit circuit has such main functions: selective filtering
correction for input composite video signal CVBSINT, output composite video signal
CVB-SEXT, CVB/Y and chroma signal C; chroma signal processing and brightness signal
processing, as detailed in Fig. 6.
6.
Color decoder unit circuit
The color decoder unit circuit consists of the PLL/VCXO circuit, PAL/NTSC
identification circuit, SECAM identification circuit, (R-Y)/(B-Y) demodulator and automatic
system manager ASM, as detailed in Fig. 7.
7.
RGB primary signal processor and control unit circuit
This unit circuit mainly consists of two parts, the processing of YUV/RGB video
component signal and primary signal, and RGB control, as detailed in Fig. 8.
(II) Main composition and functions of main pins
1. Main composition
This chassis is in standard single-board structure in the overall layout, the mature Sanyo
power supply is used, and the position numbers are arranged to international standard. Its
main IC’s and their functions are as follows:
Position No. 0- AV unit
Position No. 1- small signal unit
Position No. 2- video amplification unit
Position No. 3- vertical unit
Position No. 4- horizontal unit
Position No. 5- intermediate amplification and decoding unit
Position No. 6- sound unit
Position No. 7- remote control unit
Position No. 8- power supply unit
Position No. 9- other units
①
N701 MTV880C.V1.1 (CPU)
②
N702 PCF8594/24C04 (E
2
PROM)
③
N501 OM88388 (color single-chip small signal processor)
④
N601 TDA7056B (single-channel power amplification)
N602 TDA7057AQ (stereo power amplification)
⑤
N301 TDA8351 (large screen vertical module)
TDA8356 (small screen vertical module)
⑥
N201 TDA6108JF/TDA6107JF (only for some models)
⑦
N001 HEF4053 (AV switch, only for models with AV stereo)
⑧
V101 ENV59D68F1G (38MHz)/ENV9D68FIE (38.9MHz)
⑨
T402 FBT (flyback transformer)
2. Functions of main pins of ICs’
[1]CPU MTV880C.V1.1 (Note: 0—low level, 1— high level)
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