Daewoo WP-895, Service Manual

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Service manual WP 895/895F, CP885/885F, CP485F
Pin No. Pin Name Type Short description
59 ANA_IN1- In IF common
60 NC Not Connected
61 TESTEN In Test pin
62 XTAL_IN In Crystal oscillator
63 XTAL_OUT Out Crystal oscillator
64 NC Test pin
4-3 TDA 4470-Multistandard Video-IF and Quasi Parallel Sound Processor
4-3-1- Description
The TDA 4470 is an integrated bipolar circuit for multi-standard video/sound IF (VIF/SIF) signal processing in
TV/VCR and multimedia applications. The circuit processes all TV video IF signals with negative modulation
(e.g., B/G standard), positive modulation (e.g., L standard) and the AM, FM/NICAM sound IF signals.
4-3-2- Features
- 5V supply voltage ; low power consumption.
- Active carrier generation by FPLL principle (frequency-phase-locked-loop) for true synchronous demodulation.
- Very linear video demodulation, good pulse response and excellent intermodulation figures.
- Alignment-free AFC without external reference circuit, polarity of the AFC curve is switchable.
- VIF-AGC for negative modulated signals (peak sync. detection) and for positive modulation
(peak white/black level detector).
- Tuner AGC with adjustable take over point.
- Alignment-free quasi parallel sound (QPS) mixer for FM/NICAM sound IF signals.
- Intercarrier output signal is gain controlled (necessary for digital sound processing).
- Complete alignment-free AM demodulator with gain controlled AF output.
- Separate SIF-AGC with average detection
- Two independent SIF inputs
- Parallel operation of the AM demodulator and QPS mixer (for NICAM-L stereo sound).
4-3-3- Pinning
Pin Symbol Function
1,2 V
i,SIF1
SIF1 input ( symmetrical)
3 V
SW
Input selector switch
4,9,16 GND Ground
5 V
AGC
SIF-AGC (time constant)
6,7 V
i,VIF
VIF input (symmetrical)
8 C
AGC
VIF-AGC (time constant)
10 R
TOP
Take Over Point, tuner AGC
11 I
tun
Tuner AGC output current
12 V
O,VID
Video output
13 V
SW
Standard switch
14 V
SW
L’switch
15 C
bl
Black level capacitor
17 C
ref
Internal reference voltage
18 LF Loop Filter