TV signal processor-Teletext decoder
with embedded µ-Controller
The various versions of theTDA935X/6X/8X series
combine the functions of a TV signal processor together
with a µ-Controller and US Closed Caption decoder. Most
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 S-DIP envelope with 64 pins.
The features are given in the following feature list. The
differences between the various ICs are given in the table
on page 4.
Preliminary Device Speciﬁcation
• Multi-standard vision IF circuit with alignment-free PLL
• 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.
• The mono intercarrier sound versions have 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.
• Source selection between ‘internal’ CVBS and external
CVBS or Y/C signals
• Integrated chrominance trap circuit
• Integrated luminance delay line with adjustable delay
• Asymmetrical ‘delay line type’ peaking in the luminance
• Black stretching for non-standard luminance signals
• Integrated chroma band-pass filter with switchable
• Only one reference (12 MHz) crystal required for the
µ-Controller, Teletext- and the colour decoder
• PAL/NTSC or multi-standard colour decoder with
automatic search system
• Internal base-band delay line
• RGB control circuit with ‘Continuous Cathode
Calibration’, white point and black level off set
adjustment so that the colour temperature of the dark
and the light parts of the screen can be chosen
• Linear RGB or YUV input with fast blanking for external
RGB/YUV sources. The Text/OSD signals are internally
supplied from the µ-Controller/Teletext decoder
• Contrast reduction possibility during mixed-mode of
OSD and Text signals
• Horizontal synchronization with two control loops and
alignment-free horizontal oscillator
• Vertical count-down circuit
• Vertical driver optimized for DC-coupled vertical output
• Horizontal and vertical geometry processing
• Horizontal and vertical zoom function for 16 : 9
• Horizontal parallelogram and bow correction for large
screen picture tubes
• Low-power start-up of the horizontal drive circuit
1999 Sep 28