SAA5231 Datasheet, PDF (11/13 Pages) NXP Semiconductors – Teletext video processor

Philips Semiconductors
Teletext video processor
Product specification
SAA5231
20. Oscillator input (6 MHz)
See pin 18.
21. Filter 1
A filter with a long time constant is connected to this pin for the horizontal phase detector.
22. Sandcastle input pulse (PL/CBB)
This input accepts a sandcastle waveform, which is formed from PL and CBB from the CCT.
Signal timing is shown in Fig.5.
23. Pulse timing resistor
The current for the pulse generator is defined by a 68 Ω resistor connected to this pin.
24. Pulse timing capacitor
The timing of the pulse generator is determined by a 220 pF capacitor connected to this pin.
25. Video composite sync output (VCS)
The output signal is for CCT.
26. Black level
The black level for the adaptive sync separator is stored by a 68 nF capacitor connected to this pin.
27. Composite video input (CVS)
The composite video signal is input via a 2,2 µF clamping capacitor to the adaptive sync separator.
28. Text composite sync input (TCS)/Scan composite sync input (SCS)
TCS is input from CCT or SCS from external sync circuit. SCS is expected when there is no load resistor at pin 1.
If pin 28 is not connected the sync output on pin 1 will be the composite video input at pin 27, internally buffered.
handbook, full pagewidth
VIDEO
SIGNAL
(pin 27)
SANDCASTLE
INPUT
(pin 22)
0 1.5 4.7 8.5
33.5
5V
2V
0V
t (µs)
MGH186
Fig.5 Sandcastle waveform and timing.
November 1986
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