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TMDS181: AC coupling for output

Ruixin Feng
Intellectual 2515 points

Part Number: TMDS181

Hi team,

Customer need AC coupling for output, but in FPGA side, there has been already pull-up resistors. But I know that in TMDS181 side, it also requires pull-up resistors. I was wondering if you could give some advice on whether the pull-up resistors in TMDS181 side can be removed or not. If can't, how about the pull-up resistors in FPGA side, does customer need to remove them?  

Thanks!

Rayna

  • 0
    TI__Guru**** 183291 points

    Rayna

    If you are AC coupling the TMDS181 output, then you must have the 50ohm pull-up resistors to 3.3V between the TMDS181 output and the AC coupling capacitors since TMDS181 output expects to see the 50ohm termination to 3.3V. 

    For the pullup resistors between the AC coupling capacitors and the FPGA input, please check with the FPGA vendor as the requirement depends on the FPGA input termination structure.

    Thanks

    David