2025-03-11 9:12 PM
Hello,
I am currently working on a project using the STM32 series and have two specific questions regarding MCU selection:
:keycap_1: Are there any STM32 MCUs that support 5V logic levels for both input and output?
Most STM32 MCUs operate at 3.3V logic levels, but I need an MCU that can directly interface with 5V logic without additional level shifters.
:keycap_2: Do any STM32 MCUs provide a built-in feature to trigger ADC conversion during the ON-time of a PWM cycle?
I am looking for an MCU where the ADC conversion can be automatically synchronized with the PWM signal, preferably triggering at a specific percentage of the ON-time (e.g., 90% of the ON duration).
If there are any STM32 MCUs that support these features, I would appreciate any recommendations or relevant documentation.
Thank you in advance!
2025-03-11 11:17 PM
Most of STM32 IOs are 5V tolerant (look at the datasheet to see what they are). You can add external pullup resistor to 5V and set GPIO mode as open drain output, then you can use GPIO as 5V output. Of course, with all the limitations that come with this choice (reduced current source capability, slower rising edge). Five volt tolerants IOs can serve asi input for 5V signals without any limitations.
ADC conversion can be triggered by various timer signals (and synchronized with PWM) probably on any STM32 (and probably on any recent MCU).
Relevant documentation is "Datasheet" for GPIOs informations and Reference manual (for informatons about timers, ADC and their connection).