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Associate III
April 8, 2025
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Power Supply for STM32H757xI in package WLCSP156 - decoupling capacitors

  • April 8, 2025
  • 1 reply
  • 527 views

Hello all, for STM32H757xI in package WLCSP156, I didn't find a clear explanation about connecting capacitors for power supply. 

According to the schematic from STM32H757xI  kit, it looks like all VDD_MCU pins need to connect 100 nf capacitors, 

kit.jpg

Only in my case, I can do that, since not enough place on the PCB

Power Supply_1.jpg

I wanted to ask, does it have any opportunity to connect VDD_MCU pins to each other and connect to more powerful capacitors. If yes, how can I calculate nominal for capacitors in this case 

I want to do like here

Power Supply _2.jpg



Best answer by Andrew Neil

@Ronil wrote:

Hello all, for STM32H757xI in package WLCSP156, I didn't find a clear explanation about connecting capacitors for power supply. 

According to the schematic from STM32H757xI  kit, it looks like all VDD_MCU pins need to connect 100 nf capacitors


Did you see Application Note AN4938Getting started with STM32H74xI/G and STM32H75xI/G MCU hardware development ?

via: https://www.st.com/en/microcontrollers-microprocessors/stm32h757xi.html#documentation

AndrewNeil_0-1744111757933.png

 

1 reply

Andrew Neil
Andrew NeilBest answer
Super User
April 8, 2025

@Ronil wrote:

Hello all, for STM32H757xI in package WLCSP156, I didn't find a clear explanation about connecting capacitors for power supply. 

According to the schematic from STM32H757xI  kit, it looks like all VDD_MCU pins need to connect 100 nf capacitors


Did you see Application Note AN4938Getting started with STM32H74xI/G and STM32H75xI/G MCU hardware development ?

via: https://www.st.com/en/microcontrollers-microprocessors/stm32h757xi.html#documentation

AndrewNeil_0-1744111757933.png

 

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
RonilAuthor
Associate III
April 8, 2025

Thank you so much