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ADV7180: why a bad horizontal sync?

Question asked by Beg on May 15, 2013
Latest reply on Jul 26, 2013 by DaveD

I observe the curvature of the vertical lines in the start of digitized fields (see files in the Patterns folder).

So same distortions appear on the brightness leaps within a field (see Patterns\Half.jpg).

At the "Dot Field" pattern there is a line jitter within the entire frame(see Patterns\DotField.jpg).


Synchronization made with SAV/EAV codes and has been debugged under "Blue screen" mode, that works fine.


In Waveforms\01ScopeLn24.TIF, 02ScopeLn124.TIF the signal of the white field pattern (see Patterns\WhiteField.jpg) of line #24

and #124 is shown respectively. In these files, the channel #1 shows an output synchro signal of the pattern generator, channel #2

presents the signal at the Ain1 pin of the ADV7180WBCPZ, channel #4 is the output signal at the HS pin of the ADV7180WBCPZ,

its frequency is displayed on the right, actually it is the horizontal sync frequency.

Comparing these files, I see the difference in the horizontal frequency and the bias voltage within the field.

1 Is it acceptable?


Files 03PlotLn24-26.png, 04PlotLn24-26_2.png, 05PlotLn124-126.png represent the Y - component plots of the ADV7180WBCPZ pixel port

output of the white field pattern. Comparing 03PlotLn24-26.png against 04PlotLn24-26_2.png it is possible to notice a line jitter

at the begin of field. In the middle of the field, the jitter is absent, see 05PlotLn124-126.png.


Other files show the ADV7180WBCPZ pixel port output data.


2 Any idea of pooor horizontal sync?