Skip to main content
SBart.5
Associate II
March 6, 2023
Solved

STKNX, 100 µF capacitor CVDDHV: Can I use multiple MLCC in parallel instead of one electrolytic capacitor or are there certain characteristics of the electrolytic capacitor that are needed in the circuit? Datasheet "DS12399 - Rev 3 - May 2021", Table

  • March 6, 2023
  • 3 replies
  • 1168 views

..

    This topic has been closed for replies.
    Best answer by Peter BENSCH

    Welcome, @SBart.5​, to the community!

    Electrolytic capacitors are usually preferred at this point for price reasons. Using MLCC instead should not be a problem, but MLCC, especially when connected in parallel, usually have a much lower ESR than electrolytic capacitors, which can lead to large peak currents when switching on and possibly exceed the KNX limits. If necessary, this can be achieved by adding a series resistor.

    Does it answer your question?

    Regards,

    /Peter

    3 replies

    Peter BENSCH
    Peter BENSCHBest answer
    Technical Moderator
    March 6, 2023

    Welcome, @SBart.5​, to the community!

    Electrolytic capacitors are usually preferred at this point for price reasons. Using MLCC instead should not be a problem, but MLCC, especially when connected in parallel, usually have a much lower ESR than electrolytic capacitors, which can lead to large peak currents when switching on and possibly exceed the KNX limits. If necessary, this can be achieved by adding a series resistor.

    Does it answer your question?

    Regards,

    /Peter

    SBart.5
    SBart.5Author
    Associate II
    March 6, 2023

    Thank you for your quick reply, that answers my question.

    In our case we do not have enough space in the height for an electrolytic capacitor, so we need an alternative.

    Regards, Sebastian

    Peter BENSCH
    Technical Moderator
    March 6, 2023

    Great!

    If the problem is solved, please mark this thread as answered by selecting Select as best, as also explained here. This will help other users find that answer faster.

    Good luck!

    /Peter