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Re: [802.3_10SPE] [T1S-PSD] EMC and EMI requirements



Hello Eric,
thank you for your comments on my presentation. I perfectly understand your point and I think that going for 40dB MC would be challenging but possibly feasible.
Please, find below the additional simulation results.



Thank you,
Kind Regards,

Piergiorgio


------ Original Message ------
From: "DiBiaso, Eric" <eric.dibiaso@xxxxxx>
To: STDS-802-3-10SPE@xxxxxxxxxxxxxxxxx
Sent: 18/1/2018 19:47:37
Subject: Re: [802.3_10SPE] [T1S-PSD] EMC and EMI requirements

Piergiorgio,

 

Thanks for the presentation today looking at EMC/EMI and the adopted Mode Conversion Requirement.  

 

As you are probably aware, the goal for some OEMs is to reuse existing cables and connectors for the 10Base-T1S to keep the system cost to a minimum.   This was the background for the already adopted link segment requirements.   The MC Limit was first suggested by BMW based on some testing they did with an actual vehicle harness, see link below.

 

http://www.ieee802.org/3/cg/public/adhoc/kaindl_matheus_3cg_01_0817.pdf

 

Based on all the testing I have done, I’m ok with tightening the MC requirement.   However, going all the way to match the 100Base-T1 MC requirement of -43dB will eliminate some connector choices that OEMs would potentially use for 10Base-T1S.  Please see the graph below copied from page 16 of my September Interim contribution.    (http://www.ieee802.org/3/cg/public/Sept2017/DiBiaso_Bergner_01c_0917.pdf)

 

After re-analyzing my test data, I would suggest the following MC limit given below in the new graph. 

 

 

The new green curve still allows the connector to pass the mode conversion requirement.  

 

Would you be able to test this new MC limit in a similar fashion to the presentation you gave today?  I’m very curious to see if this would give adequate results in your simulations.     

 

New Proposed MC Limit:

MC < -40dB                                 for 0->12MHz

MC < -40+20*LOG10(f/12)       for 12->200MHz

 

 

Please let me know if you have any questions. 

 

Thanks and Best Regards,

Eric DiBiaso