DP83TC813R-Q1: common mode termination

Zehui Li

Hi,

I notice some devices describe common mode termination is optional. I wonder what is the function of this? Can this be removed?

over 2 years ago

0 Gerome Cacho over 2 years ago

TI__Mastermind 40775 points

Hello,

Thank you for your query. Currently, US offices are closed for Labor Day holiday. Please expect a response during the middle of the week.

Sincerely,
Gerome

0 Gerome Cacho over 2 years ago in reply to Gerome Cacho

TI__Mastermind 40775 points

Hello,

The Common Mode Termination network is used to suppress common mode noise on the MDI. This is a widely accepted practice that is required by many OA following OEMs. We are curious about this deviation of the network? Can you please share more about these devices saying this is optional?

Sincerely,

Gerome

0 Zehui Li over 2 years ago in reply to Gerome Cacho

Intellectual 540 points

Hi Gerome，

I think CM choke is for suppressing common mode noise. 1Kohm resistor is quite large and is between two differential signal, which is more like a differential termination in my opinion. I am not sure about the performance of it. You may check TJA1100.

0 Gerome Cacho over 2 years ago in reply to Zehui Li

TI__Mastermind 40775 points

Hello,

Thank you for the reference. All of the testing for our device has been done with both the CMC and CM termination network, and is used for best practices for EMC performance following Open Alliance.

Sincerely,

Gerome

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DP83TC813R-Q1: common mode termination