TMDS442: TMDS442 I2C pull-up values

Akihisa Tamazaki

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

over 4 years ago

0 David (ASIC) Liu over 4 years ago

TI__Guru*** 139465 points

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

0 Akihisa Tamazaki over 4 years ago in reply to David (ASIC) Liu

TI__Genius 10805 points

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

0 David (ASIC) Liu over 4 years ago in reply to Akihisa Tamazaki

TI__Guru*** 139465 points

Tamazaki-san

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

Thanks

David

0 Akihisa Tamazaki over 4 years ago in reply to David (ASIC) Liu

TI__Genius 10805 points

David-san,

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

Best Regards,
Akihisa Tamazaki

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TMDS442: TMDS442 I2C pull-up values