Daewoo DTR-14D3VG, Service Manual

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14
TDA884X ( One Chip TV-processor )
(1) General Description
The TDA884X family is a pin-aligned range of single chip video and audio processors.
With this family it is possible to cover in one layout a whole range of applications from simple small screen single standard
sets (as well PAL as NTSC with built-in delay line) to full multi-standard (including SECAM) 16:9 sets. Switching from the
TDA837x family to TDA884X family has been made very easy:the SDIP packages of the families are almost pin aligned and
minimal layout adaptations are necessary. Omitting the delay line TDA4665 and SECAM add-on TDA8395 with surrounding
components, VCO coil, direct connection of U, V in-and outputs and adapting the software to access the 5 extra registers
are the most relevant changes needed.
(2) Feature
• IF
- Alignment free IF-PLL, IF frequency selection via I 2 C (no external coil needed)
- Vision IF amplifier with high sensitivity and good figures for differential phase and gain
- PLL demodulator with high linearity offering the possibility for (single standard) intercarrier stereo audio application
- Alignment PLL via I
2 C
• AUDIO
- Alignment free multi standard PLL audio demodulator (4.5 to 6.5 MHz.)
- Volume control
• Video
- Integrated fixed luminance delay line
- Integrated chroma trap (auto calibrated)
- Integrated chroma bandpass filters with switchable centre frequency (auto calibrated)
- Asymmetrical peaking circuit in the luminance channel with switchable noise coring function
- Black stretching of non standard CVBS or luminance signals, switchable via I
2 C bus
• RGB
- RGB control (brightness, contrast, saturation)
- Improved black current stabilisation (continuos cathode calibration)
- White point adjustment
- Blue stretch which offsets colours near white to blue
- Option to insert “blue back” when no video signal is available
• Input / Output
- Flexible video source select with CVBS input for the internal signal and two external video inputs(one switchable for
CVBS or Y/C).
- The output signal of the video source select is externally available ( also as CVBS when Y/C input is used).
- External audio input.
- Linear RGB input with fast blanking.
• Synchronization and Deflection
- Horizontal synchronization with two control loops and alignment free horizontal oscillator.
- Slow start and slow stop of the horizontal drive output to enable low stress start-up and switch-off from the line
circuit at nominal line supply voltage.
- Vertical count-down circuit for stable behavior with provisions for non-standard signals.
- Vertical geometry control.
- Vertical drive optimized for DC coupled vertical output stages.
- Option for blanking of PAL plus helper signal
- Option to stop the vertical deflection for Vg2 alignment
- Option to switch-off in the vertical overscan
• Control
- Full I 2 C bus control, as well for customer controls as for factory alignment.