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how to select Coupled inductor in design TIDA-00702

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Replies: 3

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is there an article about  how  how  to select Coupled inductor? why L1 is 5.5mh,why L2 is 20mH.  Now I want to Let the 4-level EFT decay below 10V, or below 0.5V, how to choose the common mode inductor? Is it possible to achieve attenuation with a common mode inductor alone?

  • Hi,

    thanks for your interest in our design.

    For the common mode inductor selection, this design refer to other designs but it doesn't do the EMC test. So you need to select the right inductor based on your test result. As for EFT test, our designs didn't do such test so I don't have very good suggestion for your question.

    regards

    huixin

  • Hi,

    as Huixin already mentioned, the exact inductor values for L1 and L2 are usually found by trial and error in order to meet the according EMC tests. This is no rocket science. It would be the best, if you bring a handful of different filtering circuits mounted with different inductor values and from different manufacturers along with the testing. This will save time and costs.

    Eventually, you could change the filter topology. But I wouldn't do that. The given two stage filter is pretty standard. There's nothing unusual with it. So, I wouldn't change it.

    Kai

  • Hi Kai,

    thanks for your explanation.

    regards

    huixin