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TMDS442: TMDS442 I2C pull-up values

Expert 8035 points

Replies: 4

Views: 50

Part Number: TMDS442

Hello team,

My customer has a question about I2C pull-up resisters values of TMDS442.

The following E2E forum,  "SCL/SDA(source side) should have 47k pullups, SCL_SINK/SDA_SINK should have 6k pullups" was written.

https://e2e.ti.com/support/interface/f/138/t/555602?TMDS442-Check-of-circuit-connection 


Would you tell me how constant values(47k and 6k) ​​are determined?    Please advise.

Best Regards,
Akihisa Tamazaki

  • Tamazaki-san

    This is defined by the HDMI spec. The spec defines a 1.5k min and 2k max pullup resistor for Source SCL and SDA, and 47K +/-10% pullup resistor for Sink SCL and SDA. I believe the 6k is a typo.

    Thanks

    David

  • In reply to David (ASIC) Liu:

    David-san,

    Thank you for your comment.

    The customer requested us to show where in HDMI specification 1.5k min and 2k max pullup resistor for Source SCL and SDA, and 47K +/-10% is written. Because the customer do not know whether 6kohms is typo or not.

    Would you please advise?

    Best Regards,
    Akihisa Tamazaki



  • In reply to Akihisa Tamazaki:

    Tamazaki-san

    Please refer to section 4.2.8 of the HDMI spec 1.4b.

    Thanks

    David

  • In reply to David (ASIC) Liu:

    David-san,

    Thank you for your kind support. It is so helpful.

    Best Regards,
    Akihisa Tamazaki