TDA4780 Datasheet, PDF (28/44 Pages) NXP Semiconductors – RGB video processor with automatic cut-off control and gamma adjust

Philips Semiconductors
RGB video processor with automatic
cut-off control and gamma adjust
Preliminary specification
TDA4780
12. Blanking to ultra black level occurs during time DG except MR in R-channel, MG in G-channel, MB in B-channel (see
Fig.10).
a) Leakage current measuring time:
LM will start after the end of vertical sandcastle (see Fig.10).
b) Vertical blanking period and cut-off measurement lines (see Fig.10):
The vertical component will be identified if it contains 2 or more burst key pulses in the event of SC5 = 1 or two
or more line pulses (H) in the event of SC5 = 0. The line counter is triggered by the leading edge.
The blanking time is valid for a vertical pulse detected by the sandcastle decoder.
The internal blank pulse is OR gated with the sandcastle vertical pulse and the end of the measurement pulses.
c) Insertion time: full line period.
d) Measurement time: line period minus horizontal period (50/60 Hz).
e) Line sequence of measuring lines (see Fig.10):
First line after end of horizontal pulse which followed the end of vertical pulse: leakage measurement LM
First line after leakage measurement pulse: red measurement MR
Second line after leakage measurement pulse: green measurement MG
Third line after leakage measurement pulse: blue measurement MB.
13. Y output can be switched to hue adjust output via I²C-bus control bit YEXH. Output without sync pulse.
Recommendation: Hue adjust DAC set to 3FH. Black level adjustable via hue adjust DAC.
14. Output can be switched to Y output via I²C-bus control bit YEXH (via I²C-bus, resolution 6-bit, bus subaddress 03H).
1997 Feb 06
28