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DS32ELX0421: EMI reduction of DS32ELX0421

Part Number: DS32ELX0421
Other Parts Discussed in Thread: DS32ELX0124

Hi team,

  I would like to consult with you about a EMI reduction of communication
  DS32ELX0421 to DS32ELX0124.

  My customer evaluated the EMI(3m) with DS32ELX0421 and DSELX0124.
  From the result,the margin was low regarding VCCI average standard.
  He wants to improve the margin.
       Please see the attached file.


  He is planning to re-evaluate the EMI(3m) on March 29(Japan time).
  If you have any measures he should try at the time of re-evaluation,
  could you please tell me those?

  I got the schematic of around DS32ELX0421 and DS32ELX0124 from my customer,
  but I can not post it on this site.
  If you could tell me your e-mail address, I share it with you.

  In addition,if you have the additional necessary information,
  please let me know.

Best regards.
Tsuyoshi Tokumoto

  • Hi Tokumoto-san,


    Shielding was the most prevalent method used to decrease EMI. Can customer try the different cable?


    One powerful method to reduce EMI is the spread spectrum technique which modulates the signal and spreads the energy over a wider frequency range. Page 13 of datasheet shows details.


    Make sure the customer is following all the PCB layout guidelines listed in the datasheet. Doing a good job with the layout could possibly reduce EMI.


    We have several recommendations regarding Channel Link or FPD Link design considerations for reducing EMI. Please attached find three app notes with guidelines for optimizing layout with EMI reduction in mind.




    7875.Use of common mode chokes in high speed data link article.pdf


    Feel free to email me the schematic at



  • Hi Dennis-san,

      Thank you very much for your reply, and I apologize for the delay in my response.
      I tell you about the current status.
      My customer plans to evaluate the new prototype that the shield of
      connector part was strengthened.

      When I get the evaluation result,I would like to consult with you about it.
       * I intend to share the new schematic with you at that time.

      Incidentally, I was not able to get the app notes that you suggested,
      because the thread had been deleted already.

    Tsuyoshi Tokumoto