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STM32H745 - unused SMPS pins

Joe.H
Senior

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.

1 ACCEPTED SOLUTION

Accepted Solutions
TDK
Guru

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

If you feel a post has answered your question, please click "Accept as Solution".

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6 REPLIES 6
TDK
Guru

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

If you feel a post has answered your question, please click "Accept as Solution".
Joe.H
Senior

Thanks

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-

 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.

Thank you very much for the fast help.

Just to be sure, (since the datasheet of the STM32H747 does not mention it) VDDLDO and VCAP are connected in the LDO bypass scenario ?