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Resiliance of ceramic caps to overvoltage?

Discussion in 'General Electronics Discussion' started by eem2am, Apr 5, 2013.

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  1. eem2am

    eem2am

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    How resilient are X7R ceramic capacitors to short term overvoltages.

    In other words, say i have a 16V, X7R, 22uF sepic capacitor, and every time i switch on the sepic, i get a 20V spike across the 16V ceramic for about 30us......is that going to be ok?

    How long will such a capacitor last.?
     
  2. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    It's worth checking the specs for the capacitor for the "dielectric withstanding voltage".

    In this case they specify 250% of the rated voltage for 5+/-1 seconds, so 30us is fine.

    However, whilst I wouldn't take this figure as a general one, the significant difference in both % overvoltage and duration suggests that you (and more importantly, your capacitor) will be fine.
     
  3. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

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  4. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Another drawback not often mentioned is their extremely brittle nature.

    edit: that's mentioned on page 2 :)
     
    Last edited: Apr 6, 2013
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