STM32F3 Discovery / STM32F303VC 5V tolerant IO

[pierric]

Posted on June 04, 2013 at 18:38

Good afternoon,

I'm a student working on a robotic project using a STM32F3 discovery evaluation board. I read that there are several IO that are 5 volts tolerant among all IOs the board have. The issue is that I can't find which outputs are 5 volts tolerant in the chip. I search several ST documentations, the web and the library... Did anyone found this information ? Any help will be appreciated ! Sincerly, P.G #stm32 #discovery

[Tesla DeLorean]

Posted on June 04, 2013 at 19:24

None of the pins are going to physically output 5V.

You'll have to check if the VOL/VOH levels output from the STM32 via it's primary supply are adequate. To get to 5V you'll need to program a pin in OD (Open Drain) mode, and use an external pull-up resistor to a 5V supply. These would need to be the same FT (Five volt Tolerant) pins listed in the data manual.

[pierric]

Posted on June 04, 2013 at 19:33

Thank you for the answer, but the issue is different :

I should have precised that the aim is to have 5 volts input without burning some inputs, as it seems that only some of theses inputs are 5 volts tolerant. I have 2 encoders that only works with TTL logic levels and therefore give me 5 volts signals to be analysed.

[Tesla DeLorean]

Posted on June 04, 2013 at 19:38

And these pins are identified in the manual for the part? No?

http://www.st.com/web/catalog/mmc/FM141/SC1169/SS1576/LN1531/PF252054

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00058181.pdf

This doesn't preclude you from adding external level conversion logic either, or resistor dividers.

[pierric]

Posted on June 04, 2013 at 20:40

Thank you for the links, I already had read this documentation but I didn't found the information... and it is available in the pinout and pin description chapter.

On page 10, we learn there are 45 ''normal'' TC/TTa GPIO and 42 ''5 volt tolerant'' FT/FTf GPIO. Later on pages 36 and following, there is all the information I needed. Many thanks, best regards, P.G