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ADV7128 artifacts in PAL

Question asked by HankZ on Jul 3, 2013
Latest reply on Jul 15, 2013 by DaveD

I’ve been evaluating the ADV7182 (Analog  to SDTV Video Decoder) for use in a

next generation product.  I’ve been comparing its performance against another part..

Overall, I’m pleased with the part, but I do have a fairly big issue.

The part will used as a composite video decoder (NTSC or PAL).  I have made

several signal measurements in NTSC and PAL (gain, freq. response, DP DG, etc.)

and the ADV7128 equal to or better than the other chip.  In NTSC mode,

playing video with scrolling text, multiple graphics layers, and high frequency

content, the ADV7182s comb filter and DNR adjustments allow for better

performance?.

However, in PAL mode,  the other part does much better.  The ADV7182 has way too

much dot-crawl, no matter the  PAL comb-filter register settings.  Are there

any other adjustments to improve the PAL comb filter?

Also ,the evaluation board that I’m using is EVAL-ADV7182/7280BZ (REV. A) 

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