
Philips Electronics
GENERAL DESCRIPTION
The various versions of the TDA955X/6X/8X PS/N1 series combine the functions of a video processor together with a µ-Controller and US Closed Caption decoder. Several versions have a Teletext decoder on board. The Teletext decoder has an internal RAM memory for 1or 10 page text.
The ICs are intended to be used in economy television receivers with 90° and 110° picture tubes. The ICs have supply voltages of 8 V and 3.3 V and they are mounted in an S-DIP 64 envelope.
FEATURES
TV-signal processor
• Multi-standard vision IF circuit with alignment-free PLL
demodulator
• Internal (switchable) time-constant for the IF-AGC circuit
• A choice can be made between versions with mono intercarrier sound FM demodulator and versions with QSS IF amplifier. In the QSS versions without East-West output an AM/FM mode can be activated. In that case both the QSS amplifier (for AM demodulation) and the FM demodulator are available.
• The mono intercarrier sound circuit has a selective FM-PLL demodulator which can be switched to the different FM sound frequencies (4.5/5.5/6.0/6.5 MHz).
The quality of this system is such that the external band-pass filters can be omitted.
• The FM-PLL demodulator can be set to centre frequencies of 4.74/5.74 MHz so that a second sound channel can be demodulated. In such an application it is necessary that an external bandpass filter is inserted.
• The QSS amplifier and mono intercarrier sound circuit of some versions can be used for the demodulation of FM radio signals
• Source selection between the ‘internal’ CVBS and one external CVBS or Y/C signal
• Integrated chrominance trap circuit
• Integrated luminance delay line with adjustable delay time
• Picture improvement features with peaking (with switchable centre frequency, depeaking, variable positive/negative overshoot ratio and video dependent coring) and blue- and black stretching