Voltage of microcontrollers.

Hello everybody and thank you always for the help.

I have been working with PICs for a time now. So far I have been dealing with PIC18F2550, 4553, 2553, etc which are 5V based micros. I have also worked with PIC18F45K20 which is 3.3V based . This info is on the datasheet I know...

Now I am interested in several other architectures:

- STM32. Specifically STM32F091 Nucleo https://www.st.com/web/catalog/tools/FM116/CL1620/SC959/SS1532/LN1847/PF260944

-Open103 https://www.waveshare.com/wiki/Open103R#Resources

-Stellaris LaunchPad https://www.mouser.com/ds/2/405/lm4f120h5qr-124014.pdf

-FM3 MB9BF618T

And call me a fool but I can't find if these are 5V based or 3.3V based...

I know to connect a 5V one to a 3.3 V you need a convertor, some kind of interface but I am not interested in that right now. Just want to know which voltage the pins carry.

(Note: I notice that sometimes you power these board through the USB. Now I think that gives 5V power to these boards. But I am not asking for what kind of power device you have to connect, but about the pins. This because sometimes even if you power it with 5V there is a transformation inside to other voltage....

Thanks a lot for any helpful advice

-Stellaris LaunchPad https://www.mouser.com/ds/2/405/lm4f120h5qr-124014.pdf

PDF page 1150.

KeepItSimpleStupid said:

-Stellaris LaunchPad https://www.mouser.com/ds/2/405/lm4f120h5qr-124014.pdf

PDF page 1150.

Click to expand...

Thank you for your reply. By reading what you indicated, I can understand that Stellaris is 3.3V based and that the pins can sink or source around 30mA (variying with their position though). So I can safely use it with 3.3 equipment right.

I have another question but will leave it for later... Now trying to check the other platforms....

Basically it's a 3.3 V part with 5V tolerant pins with and without power applied for the most part.