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Joe.H
Associate III
January 11, 2022
Solved

STM32H745 - unused SMPS pins

  • January 11, 2022
  • 2 replies
  • 2738 views

I don't use the internal Step Down regulator. How should the pins be tied?

Should VDDSMPS be tied to VDD and VSSSMPS to GND with VLXSMPS and VFBSMPS left open?

OR - should they ALL be left open?

Documentation only speaks as if they are to be used - no comments on what to do if not used.

Best answer by TDK

This app note for STM32H7A/B shows them as grounded/floating. Can't imagine it's different for the H745.

0693W00000HrI9yQAF.png 

0693W00000HrIAhQAN.png 

https://www.st.com/resource/en/application_note/an5307-getting-started-with-stm32h7a37b3-line-and-stm32h7b0-value-line-microcontroller-hardware-development-stmicroelectronics.pdf

2 replies

TDK
TDKBest answer
Super User
January 11, 2022
"If you feel a post has answered your question, please click ""Accept as Solution""."
Associate
October 8, 2024

Hi,

is the same solution possible for the STM32H747XIH6?

I want to fully bypass the internal LDO and SMPS.

Moritz__0-1728388150865.png

Thank you-

mƎALLEm
Technical Moderator
October 8, 2024

 STM32H747 and STM32H745 have the same config from power settings point of view.

"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."
Joe.H
Joe.HAuthor
Associate III
January 11, 2022

Thanks