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ADV7850 Tempture question

Question asked by Kevin1102 on Mar 2, 2017
Latest reply on Mar 6, 2017 by JeyasudhaMuthuPerumal

Hello,

 

Could you reply some comments and any will be side effects for the registers adjusting?

Customer have some ADV7850 heat question during below condition.

Input Signal: CVBS or S-Video
Operation Temp.:Indoor
Input Signal, output eye diagram, screen show and schematics as attachment.

Failure Description: abnormal output show signal show noise 

Error ratio:6/343

 

They try to adjust the ADV7850 Reg.s several parameters can be adjusted and improve the problem.

1. IO Map 0x0B.1 (core_pdn) & 0x0C.5 (power_down) can effectively improve the problem.

    But occasionally fail below about 1/50 ~1/100 the probability.

2. TX_Main 0x3B[4:3] (PLL pixel repetition) input sources is CVBS or S-Video, Set this to x2(value=01)  

             2.1 It was okay set the repetition to another mode and return it when recognized video source,              

             2.2 Measurement of the rear end of the decode TLL signal,

                   a slight (impetuous point) clock will crush every once in a while.                     

PS:A. High temperature will make the phenomenon worse

      B. Sometimes a high temperature will become normal or work for a period of time will be better.

           If the screen is normal, it will not happen again (unless switch source or power ON-OFF) 

Could you reply some comments and any  there will be side effects for the registers adjusting?

Regard,

Kevin Tsai

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