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ADV7180 video input RF noise immunity

Question asked by shuhn on Jan 7, 2014
Latest reply on Jan 23, 2014 by Rob.Analog

I use an ADV7180 for composite NTSC video inputs in a display and recently my customers have begun showing interest in using the video inputs for back cameras on industrial vehicles.


What I have encountered during EMC testing is that during radiated immunity (SAE J1113-21, 150V/m AM and CW, from 200MHz - 3.2GHz), the video will show various levels of interference at certain frequencies.  Most are minor, with the video still very much viewable, but it can progress to the point where the video is totally disrupted and it will occasionally totally lose sync and the video will "lock" at which point the decoder needs to be reset to recover it.  Obviously, this is of some concern when using a backup camera.


My question is what is the best way to harden the video inputs against RF on the video signal?  Are there filter settings in the ADV7180 or is there some sort of standard external front end hardware filters to help prevent this?


I have attached a PDF of my circuit.  One note is that the video ground and main ground are single point connected at the connector, which is not shown on the page that I attached.  The video signals are also buried on internal layers adjacent to a ground plane and the video ground surrounds the three video signals as guard traces.