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NAbun.1
NAbun.1
Associate II
Sep 21, 2022 1:19 AM UTC
Solved

How to connect VBAT on STM32H7 when not using a battery?

Section 6.4.4 of RM0433 is the only place I could find that says what to do with VBAT rail when not using a battery. It says the following:

If no external battery is used in the application, it is recommended to connect VBAT externally to VDD through a 100 nF external ceramic capacitor.

Does it actually mean "through"? That wording implies this:

0693W00000SvqqtQAB.png 

...but I don't see how that make sense.

Does anyone else read it differently?

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    Peter BENSCH
    Peter BENSCHBest answer
    ST Technical Moderator
    Sep 21, 2022 9:46 AM UTC

    Welcome, @NAbun.1​, to the community!

    This is indeed misleading and means that you should connect VBAT to VDD and from that connection connect the capacitor to GND.

    Does it answer your question?

    Regards

    /Peter

    In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
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    4 replies

    Peter BENSCH
    Peter BENSCHBest answer
    ST Technical Moderator
    Sep 21, 2022 9:46 AM UTC

    Welcome, @NAbun.1​, to the community!

    This is indeed misleading and means that you should connect VBAT to VDD and from that connection connect the capacitor to GND.

    Does it answer your question?

    Regards

    /Peter

    In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
      NAbun.1
      NAbun.1Author
      Associate II
      Sep 22, 2022 6:12 PM UTC

      Thank you for the warm welcome! I am just getting into the STM32 micros and have a lot to learn.

      I believe you did answer my question, thanks!

      0693W00000Sw1tAQAR.png

      Peter BENSCH
      Peter BENSCH
      ST Technical Moderator
      Sep 23, 2022 7:49 AM UTC

      Great! Wish you much success working with the STM32!

      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.

      Regards

      /Peter

      In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
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