PDi PDI-P23LCD, Service Manual

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PDI-P23LCD SERVICE MANUAL
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57
CIRCUIT DESCRIPTIONS
2. VCT 49xxi SECTION.
Device : VCT 49xxi
Features : PSSDIP88-1/-2 package
PMQFP144-2 package
Submicron CMOS technology
Low-power standby mode
Single 20.25-MHz reference crystal
8-bit 8051 instruction set compatible CPU
Up to 256 kB on-chip program ROM
WST, PDC, VPS, andWSS acquisition
Closed Caption and V-chip acquisition
Up to 10 pages on-chip teletext memory
Multi-standard QSS IF processing with single SAW
FM Radio and RDS with standard TV tuner
TV-sound demodulation:
Baseband sound processing for loudspeaker channel:
CVBS, S-VHS, YCrCb and RGB inputs
4H adaptive comb filter (PAL/NTSC)
multi-standard color decoder (PAL/NTSC/SECAM)
Nonlinear horizontal scaling “panorama vision”
Luma and chroma transient improvement (LTI, CTI)
Non-linear color space enhancement (NCE)
Dynamic black level expander (BLE)
Scan velocity modulation output
Soft start/stop of H-drive
Vertical angle and bow correction
Average and peak beam current limiter
Nonlinear and dynamic EHT compensation
Black switch off procedure (BSO)
1) Description
The VCT 49xxI is an IC family of high-quality singlechip TV processors. Modular design and
deep-submicron technology allow the economic integration of features in all classes of single-
scan TV sets. The VCT 49xxI family is based on functional blocks contained and approved in
existing products like DRX 396xA, MSP 34x5G, VSP 94x7B, DDP 3315C and SDA 55xx.
Each member of the family contains the entire IF, audio, video, display, and deflection
processing for 4:3 and 16:9 50/60-Hz mono and stereo TV sets. The integrated microcontroller
is supported by a powerful OSD generator with integrated Teletext & CC acquisition including
on-chip page memory.