TMDS171: Input to reversed polarity

Shuji Ishiwata

Mastermind 8880 points

Part Number: TMDS171
Other Parts Discussed in Thread: SN65DP149,

Tool/software:

Hi All,

I have a question about TMDS171 and SN65DP149.

Is it possible to input negative to D2p and positive input to D2n as shown in the figure below?

Since it is a retimer, I believe it cannot accept inputs with reversed polarity. Is my understanding correct?

Best Regards,
Ishiwata

over 1 year ago

0 David (ASIC) Liu over 1 year ago

TI__Guru**** 192301 points

Ishiwata-san

Both TMDS171 and DP140 can support input polarity swap. Please note polarity swap only works when in retimer mode. When this function is enabled and the device is in automatic cross over mode between redriver and retimer modes, care must be taken to avoid losing polarity swap. When the data rate drops to the redriver level, the polarity swap is lost.

Thanks

David

0 Shuji Ishiwata over 1 year ago in reply to David (ASIC) Liu

Mastermind 8880 points

Hi David-san,

Thank you for your answer.

Is it okay to swap the polarity of the CLK when in retimer mode?

Also, is it okay to mix different polarities like the ones below?

Best Regards,
Ishiwata

+1 David (ASIC) Liu over 1 year ago in reply to Shuji Ishiwata

TI__Guru**** 192301 points

Ishiwata-san

Polarity swap exchanges the N and P channel polarity in each input lane. But please note the polarity swap is only available to RETIMER mode. The polarity swap function will be lost if TMDS171 and DP149 are switched to REDRIVER mode.

Thanks

David

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TMDS171: Input to reversed polarity