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ADV7842 multiburst response issue

Question asked by benwang on Mar 24, 2015
Latest reply on May 28, 2015 by benwang



I have a issue with ADV7842, that is when multiburst pattern is pumping into ADV7842 through HDMI In & output through HDMI Out, the signal reponse in scope will have some attenuation for Cb & Cr separately, while Y is without any attenuation, as following picture shows (in the picture the left is for Y multiburst, the middle & and right are Cb & Cr multiburst).

Since the source is YCbCr4:4:4 HDMI format, and the output is YCbCr4:2:2 HDMI, so only 4:4:4 to 4:2:2 decimation is implemented inside ADV7842.

The issue is critical since the attenuation on Cb & Cr will impact overall video performance.

My question is whether or not the issue is due to 4:4:4 to 4:2:2 decimation? and any way to improve it? does ADI do the similar test for HDMI input & output?


Thank you