Electrical – STM32F303 Microcontroller open drain GPIO, Can it reach / be pulled up to 5 Volts

gpiomicrocontrolleropen-drainstm32stm32f3

I hope you are all doing well… :).

I'm working on a project with pulse width modulation however I need my logical high output to be 5V. However, as my Vdd is 3.3V, the output high level is approximately 2.9V however this isn't sufficient for my needed purpose..

Somebody suggested that I configure the IO pins to open drain mode which I did actually through CubeMX, and I connected the pin to a resistor and that resistor to 5V.. However, the output of the logical High level is still around 2.8V..

I have looked through the user manual of the microcontroller which is namely a stm32f303vct6 but I couldn't find anything literally anything related to whether the pins can be pulled up to 5V or not, and if so then which pins exactly are 5V tolerant..

Could you please shed some light I may follow. I really appreciate it… I've been searching for a couple of hours online but to no avail..

Thank you!

Best Answer

I have looked through the user manual of the microcontroller which is namely a stm32f303vct6 but I couldn't find anything literally anything related to whether the pins can be pulled up to 5V or not, and if so then which pins exactly are 5V tolerant..

This information is in Table 13 ("STM32F303xB/STM32F303xC pin definitions") of the microcontroller datasheet -- it starts on page 35 of the current revision.

All pins with the letters "FT" ("five-volt tolerant") or "FTf" in the "I/O structure" column are 5V tolerant, and can be pulled up to 5V. Make sure that the pin is configured as open-drain, and internal pullup/pulldown resistors are disabled.

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