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Polymer Capacitor Quiz

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Test your polymer capacitor knowledge on how they achieve benefits such as a low ESR, improved stability, and greater tolerance for high ripple currents.

Passive Components | Resource | Experimenting with Polymer Capacitors

Polymer Capacitors

Polymer Capacitors
Complete our Polymer Capacitors course, earn 100% on the quiz, leave a comment in the document...

element14 has been talking about polymer capacitors a lot in the last few months. Before we talk too much, we thought we would give Community members a chance to show their stuff. We wrote a 25-question quiz on polymer capacitors for you to take. Have fun!

After you have answered all the questions, click "Submit Answers." Once you have scored a 100%, leave a comment on this page, and give the page a rating and you will earn a Polymer Capacitor badge. If you don't get a perfect score, that's fine. You will be given a link to the sources used to write the quiz. You can take it as many times as you want.

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  • in reply to rscasny

    Randall,

     

    I read through that document again (I read through once while doing the quiz), and I didn't see anything regarding distortion performance. There are MLCC vs. polymer comparative graphs showing several different parameters (e.g. frequency and temperature rating charts), and a brief discussion of MLCC dielectric material categories (which influence distortion performance), but no information specifically comparing distortion performance of common MLCC dielectrics to the putative polymer replacements (e.g. C0G/NP0, X5R, and X7R vs. SP-Cap, POS-Cap, and OSCON.)

    Basically all of the board-level design and analysis work I do is for audio (or even more demanding, audio test/measurement), and distortion is one of the most important parameters to consider when selecting capacitors in audio use. If I am to start using polymer capacitors, I need to know how they compare to the MLCCs and electrolytics they would be replacing.

  • in reply to rusgray

    Hi!

    I wonder if we could try measuring it.. I'm guessing nothing is worse than X5R/X7R, and that on the other hand these polymer caps are very unlikely to be as good as plastic film (otherwise capacitor manufacturers would be branding polymer caps as audio-grade and charging a lot more) but I don't know how it compares to electrolytic. Also a DC bias could be needed, since had a design that briefly had reversed polarity.

    In the absence of real audio test equipment, the modern way to test it seems to be to use high-end sound cards and signal processing digitally, but maybe an old method from RF techniques could be used,  just at a lower frequency. There the RF engineers would try to filter out the fundamental in the analog domain, and just observe the remnants with a spectrum analyzer. For audio ordinarily that would not be possible with a typical SA, but the new FPC1000/1500 goes to an incredibly low 5kHz. The other problem is how to do the filtering (a crystal filter is hard nowadays, because such low frequency large xtals are not manufactured any more), but an LC filter could be devised using 'Elsie' software.

    If there's interest, maybe we can as a community devise a test method, since several of us have access to a SA.. whereas I don't have a sound card that would be adequate for such a test : ( I don't know if others do.

  • in reply to shabaz
    but I don't know how it compares to electrolytic

     

    Keep in mind that what the industry calls "polymer capacitors" are still electrolytic capacitors made with aluminum (or tantalum). The polymer is part of the cathode, not the dielectric. Distortion isn't going to be much different from Al or Ta.

     

    (It would have been better to call them "polymer electrolytic" to avoid confusing them with plastic film, but no one has done a great job of using the proper name.)

  • in reply to baldengineer

    Hi James,

     

    I don't expect them to be much different to alu electrolytic, otherwise firms would have leapt at the chance to charge plastic film prices.

    I'm still curious to do the test to see if it is measurable this way. I was thinking about how to go about it, and it's applicability for reuse too, because the same procedure could be used to test audio amps too.

     

    Anyway, I'm just throwing the idea out there.. to see if is interesting or not. I've plenty to work on, so won't pursue this unless there's a real need.

  • in reply to panasonic-expert

    Seeing this immediately reminded me of the Oscilloscope probe shock video by EEVblog.

     

    I'd definitely think about this in the future for sensors on machinery.  (Though to be fair the only problem I've had so far is Large SMT electrolytic's falling off if not glued.  we changed to through hole on future builds.)

     

    Dan.