STM32 and Switched Mode Power Supply

[carlosdelfino]

In some readings, I saw that there are some STM32s that can be used to control Switched Mode Power Supplies. Are there any suggestions for articles with more details on the subject?

I am writing a book about "SMPS" and would like to dedicate a section of the book to microcontrollers specialized in switching control in "SMPS".

[AScha.3]

Most of the stm32 can be used for smps...especially with hi-res counter HRTIM , so see:

https://www.st.com/resource/en/application_note/an4539-hrtim-cookbook-stmicroelectronics.pdf

https://www.st.com/resource/en/application_note/an4277-how-to-use-pwm-shutdown-for-motor-control-and-digital-power-conversion-on-stm32-mcus-stmicroelectronics.pdf

+

https://www.youtube.com/watch?v=7FfBoeuk_Gc

https://www.youtube.com/watch?v=byM8th1Ubmc

 

https://www.eevblog.com/forum/microcontrollers/looking-for-easy-way-to-design-digital-controlled-smps/

 

 

 

software for smps design :

https://www.st.com/en/development-tools/digital-power-conversion-software-development-tools/products.html

 

 

[tjaekel]

Hi carlosdelfino,

it looks like your are now all over all the places (discussion here)... (cool).

No: "...STM32s that can be used to control Switched Mode Power Supplies...": they have an SMPS inside.

OK: you could use a TIM, PWM, ... in order to control an external SMPS.

SMPS in MCUs: (as I understand):

- MCU has integrated SMPS feature, e.g. to generate waveform for a buck-down converter,
- it needs still external components, esp. the coil (inductor)
- the SMPS inductor is not possible to be integrated into silicon (chips)

SMPS features are great:
- the provide a better efficiency, less power burned - so they are provided for "low power" applications,
  MCU vendors provide option to toggle between SMPS and LDOs (e.g. STM32)

But they are "bad" in terms of signal quality:
- the SMPS "noise" can travel into analog signals, e.g. ADC, OpAmps, ...
- therefore, often an option to have still LDOs on MCUs (or to use external LDOs)

I work at a chip design company and the big picture I know (and I can share):
- yes, SPMPS often inside chips (e.g. MCU), even needing external components (coil)
- but also with requirements for external components (and careful PCB design) - components very close to chip pins
- we use (in "Mixed Signal Application Products") still a lot of analog (internal LDOs), esp. when it comes
  to power the analog parts, to do analog signal processing (ADC, DAC)

SMPS are good for digital signals, but when it comes to combine digital with analog signals (e.g. sensitive sensor data) - not so easy (or complicated to remove the SMPS noise or to be EMI conformant).

[carlosdelfino]

I have been browsing the community in search of knowledge. And I believe that the best way to learn is by talking on the forums.

SMPS, despite being highly efficient, really leave something to be desired due to their noise.

In my first readings, I thought that there was something special about the STM to produce SMPS, but now I understand that they are integrated into them.

But I think that with the STM32F0 line it is possible to produce excellent alternatives to specialized chips, if there are AD converters that perform sensing.

I am writing a book and starting a website (https://fonteschaveadas.com) about switching power supplies that is the result of my notes and studies on the subject. I am still a learner, but I decided to document everything I learn in order to share it with other colleagues.

[Imen.D]

Hello @carlosdelfino ,

I added these ST articles:

• Basics of power supply design for MCU - stm32mcu
• How do I connect the STM32's SMPS (Switched-Mode P... - STMicroelectronics Community

Good Luck!