6.3V caps on 5V rail - not recommended?

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  • espresso
    Member
    • Aug 2008
    • 24
    • Serbia

    #1

    6.3V caps on 5V rail - not recommended?

    Would it be safe to put 6.3V capacitors on 5V rails in PC power supplies?
    I read somewhere that in PC supplies one should use 10V caps on 5V rails.
    And for example, National Semiconductor's datasheet for switching regulators states:
    The capacitor's voltage rating should be at least 1.5 times greater than the output voltage.
    Are there any voltage spikes that can harm the capacitors in the long run?
    I bought some FM Panasonics to replace the existing caps but they are 6.3V rated unlike the original ones which are 10V.
    Also, Panasonics have much lower esr than the caps I used before so I hope replacing won't cause instability.
  • acstech
    GrumpyModerator
    • Jul 2007
    • 1432
    • USA

    #2
    Re: 6.3V caps on 5V rail - not recommended?

    As long as they're quality caps I wouldn't worry about putting 6.3v caps on a 5v rail. Panasonic FM is a quality cap, so I wouldn't worry about it.
    A man convinced against his will is of the same opinion still.

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