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

Forum|Forum|3 years ago
September 21, 2022
4 replies
3938 views

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:

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

Does anyone else read it differently?

This topic has been closed for replies.

Best answer by Peter BENSCH

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

Peter BENSCHBest answer

ST Technical Moderator

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.1Author

Associate II

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!

Peter BENSCH

ST Technical Moderator

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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