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ADV7393 color bar issue (inside test pattern) 

Question asked by kj.liu on Nov 7, 2016
Latest reply on Dec 12, 2016 by Anthony_Purcell

Hi Sir,

    Now, we met a problem in ADV7393 test pattern in our board, the abnormal always happen in particular location (fourth data yellow bar). We already checked like power ,gnd and other point might happen cross talk. even turn off the digital video data input(16 bit) , clk and Sync signal from processor. the problem is still there. it looks the output (high bit in DAC) get the wrong data when DAC sampling. 

 

    we are curious since it's whole ADV7393 inside test signal (color bar) and it should not happen mismatch(it looks this data of color bar is installed in the chip and just through DAC transition to generate CVBS).   

 

   we though if we could adjust the phase and this peak might disappear. does the register of ADV7393 provide this in SD mode? 

 

5v switching power v.s video out

5v switching power v.s video out

 

3.3v LDO v.s video out

1.8v LDO v.s video out

 

only Y signal 

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