EMI filter design

Discussion in 'General Electronics Chat' started by TAKYMOUNIR, Mar 15, 2016.

  1. TAKYMOUNIR

    Thread Starter Active Member

    Jun 23, 2008
    351
    1
    I need to understand how to design EMI filter , is there any good book or website talk about this
     
  2. mcasale

    Member

    Jul 18, 2011
    210
    12
    I assume you're talking about a line filter for some type of product?

    Did you try to Google "EMI filter"?

    Usually, line filters are series LC filters scaled for high frequencies of interest.

    You will want to filter common-mode RF and each line as well.

    Does this need to meet CE/UL/CSA/... ?
     
  3. TAKYMOUNIR

    Thread Starter Active Member

    Jun 23, 2008
    351
    1
    i did google it , i did not find a good article about this, yes this will meet UL.
     
  4. andrewmm

    Active Member

    Feb 25, 2011
    30
    6
    EMI, like all 'filtering' in real life is a guessing game,

    Sorry ,

    there are great books on it, have look on your favourite web site, expect to pay USD 150 though.

    there are lots of 'standard' ways of doing the filtering, and as many exceptions,

    General , one designs in depth, with emc / esd / emi always in mind, and trying to retrofit is a long road of hardship.

    If you need to meet a medical standard, then good luck retro fitting.
     
  5. JohnInTX

    Moderator

    Jun 26, 2012
    2,347
    1,029
    Have you checked out Corcom? They probably already have what you need. If nothing else, you can read up on their application data. I've used a lot of their stuff and never failed any compliance tests. Download the Selector Chart to see what they have for various applications.

    Good luck.
     
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  6. mcasale

    Member

    Jul 18, 2011
    210
    12
    What circuitry is the filter feeding? A power supply, or what?
     
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  7. saeedmns68

    New Member

    Mar 16, 2016
    1
    2
    The attached file will help U very much,have any question,message me
     
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  8. bertus

    Administrator

    Apr 5, 2008
    15,648
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    TAKYMOUNIR likes this.
  9. AnalogKid

    Distinguished Member

    Aug 1, 2013
    4,542
    1,251
    I was going to describe why there is no guesswork in designing a power line filter, but the article in post #7 covers everything very well. The most difficult part is dealing with all of the safety agency requirements. The good news is that safety and EMI performance are not directly connected in filter design. For example, medical grade filters have lower leakage current, a safety issue, but the EMI performance is influenced by FCC rules (in the US), not the safety (UL) rules.

    ak
     
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  10. TAKYMOUNIR

    Thread Starter Active Member

    Jun 23, 2008
    351
    1
    is power supply (PFC circuit)
     
  11. TAKYMOUNIR

    Thread Starter Active Member

    Jun 23, 2008
    351
    1
    thanks
     
    saeedmns68 likes this.
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