AnsweredAssumed Answered

Eye diagram on the adv7511 TMDS output

Question asked by KevinChen on Aug 11, 2015
Latest reply on Aug 19, 2015 by mattp

Hi, all engineers,

 

We have ADV7511 in our design as the HDMI transmitter chip, one of our customer complained about the eye diagram on the TMDS output,

I searched the forum for this problem, only this link  https://ez.analog.com/message/51350#51350  talked about this problem, but without answer, we layout the PCB based on the reference design, and add a ESD protection chip ( TPD12S521 ) between ADV7511 and HDMI connector also, the circuitry is straightforward, we do control the impedance around 100 ohm and match the differential pair,

 

Do anyone know if any register can strengthen the eye diagram, or any hardware improvement? Thank you. We are using a 300Mhz bandwidth( not enough? ) mix signal scope to trigger the eye diagram on TMDS output, for the video stream at 1080p at 60Hz, we even cannot detect a clear eye diagram, please see the attached diagram.

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