TMDS181: Request for schematic design review

Jeffrey Chung1

Part Number: TMDS181

Tool/software:

Hi Vishesh,

Customer is trying to change the retimer from DP149 to TMDS181, so please check their schematic design and let me know the review result & the strap mode configuration for their application.

(In the schematic, SWAP/POL=N.C, I2C_EN_PIN=Low, SIG_EN=Low, PRE_SEL=N.C, EQ_SEL_A0=N.C, A1=N.C, TX_TERM_CTL=N.C)

TMDS181_Schematic.pdf

Regards,

1 month ago

0 Vishesh Pithadiya 1 month ago

TI__Mastermind 23285 points

Hi Jeffrey,

Here is the schematic review:

TMDS181_Schematic_Review_Jeffrey(11_13_2024).pdf

Additionally,

Why is the input pinout and lane count not the same?

The SDA_SRC and SCL_SRA should be coming from the HDMI connector.

Please have a look the following schematic, this can be found in the datasheet.

0 Jeffrey Chung1 1 month ago in reply to Vishesh Pithadiya

Expert 2925 points

Hi Vishesh,

Vishesh Pithadiya said:
Why is the input pinout and lane count not the same?

Customer is using RJ45 LAN connector as TMDS input connector from original 1st board with DP149.

Vishesh Pithadiya said:
The SDA_SRC and SCL_SRA should be coming from the HDMI connector.

Please have a look the following schematic, this can be found in the datasheet.

So there are no DDC data line and clock line on their application.

Please check it again under customer's application condition and let me know the 2nd review result.

Regards,

0 David (ASIC) Liu 1 month ago in reply to Jeffrey Chung1

TI__Guru**** 160846 points

Hi,

The schematic itself looks ok. One quick question, DP149 is a DP++ or AC coupled input to TMDS re-driver. TMDS181 is a DC coupled input to TMDS re-timer, do they need AC coupled or DC coupled input?

Thanks

David

0 Jeffrey Chung1 1 month ago in reply to David (ASIC) Liu

Expert 2925 points

Hi David,

Thanks for your schematic design review. As you know, Vishesh recommended TMDS181 for better signal quality of TMDS input on previous original thread. Is there any issue on their application?

Regards,

0 David (ASIC) Liu 1 month ago in reply to Jeffrey Chung1

TI__Guru**** 160846 points

Hi,

I went back and looked at that thread, you were using DP149 but with external termination, so the input is DC-coupled. In this case, I would agree with Vishesh that the TMDS181 is the right solution for this design.

Thanks

David

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TMDS181: Request for schematic design review