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Capacitor codes

  1. Jul 22, 2017 #1
    I have recently come across a datasheet for a buck converter regulator that uses the terms "c code" and "No." for certain capacitors but when going to the manufacturer datasheets for these capacitors they make no reference to any "c code" or one single number for a capacitor. If anyone could help me understand what these mean and how to find these specific capacitors from the manufacturers capacitor datasheet I would really appreciate it. The image bellow is where I have been reading these terms.

  2. jcsd
  3. Jul 22, 2017 #2


    Staff: Mentor

  4. Jul 22, 2017 #3
    Thanks I did see this website before however I'm not sure how to relate that to C code or the single digit number. The closest thing to C code was the letter that gives tolerance but it's definitely not that.
  5. Jul 22, 2017 #4


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    I have never heard of that C code
    can you please link to the specific datasheet you were looking at so we can see the context
    in which they are referred to
  6. Jul 22, 2017 #5


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    The title of the chart mentioned surface mount capacitors so the code may be valid for that only.
  7. Jul 23, 2017 #6

    jim hardy

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    I looked up that Sprague 594D series capacitor's datasheet.

    http://www.vishay.com/docs/40002/293d.pdf EDIT WRONG LINK


    They pack a lot of information in them so you have to acquire a knack for reading tech writers' minds...

    I think they're using those two characters for case size and termination type.


    Perhaps you can study the AVX and KEMET datasheets to support or refute my hypothesis ?

    It's curious your source sorts capacitors by inductance.........

    just how credible are those folks ?

    old jim
    Last edited: Jul 24, 2017
  8. Jul 24, 2017 #7

    jim hardy

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  9. Jul 24, 2017 #8


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    LOL :smile:
  10. Jul 24, 2017 #9


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    I suspect it just giving you options. For example if the voltage is 7v and you fit a 33u inductor then you fit...

    Two capacitors in position C2 if using AVX capacitors or
    One capacitor in position C3 if using Sprague or
    Two capacitors in position C4 if using Kemet.

    This might be necessary if the caps are physically a different size and have a different ESR.

    But I might be wrong.
  11. Jul 24, 2017 #10
    Sorry I should have included the entire datasheet for the buck converter regulator : http://www.ti.com/lit/ds/symlink/lm2678.pdf

    The datasheet sorts the capacitor selection table by inductance because they are recommending certain capacitor values depending on the inductance you have chosen to place on the output of the circuit.

    It would have helped if I had linked the datasheet in the first place but I believe the c codes and number refer to a specific capacitor value as they choose some for part of an example circuit.

    Thanks for all the responses though, they are much better ideas than what I had come up with myself haha
  12. Jul 27, 2017 #11


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    If you look at the footnotes for that table you will find the meaning of the numbers.

  13. Jul 27, 2017 #12
    Yeah sorry I discovered I made a mistake and there's actually a table at the beginning of the datasheet that gives the values hahah
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