NUCLEO-64 UART TX-signal at 5V with external 5V supply

[Kmax18]

I cannot find this information in the NUCLEO-64 ref. manual.

Do NUCLEO-64 boards generate a 5V UART TX-signal with an external 5V power supply (E5V pin)? Thank you.

[Peter BENSCH]

The respective U(S)ART pin is led out directly without a level shifter. Therefore, the signal level has nothing to do with the NUCLEO itself, but with the STM32 used.

Now to the individual points:

If you supply the NUCLEO via E5V, the internal VDD of normally 3.3V is generated, which supplies both the ST-LINK and the target STM32.

All STM32s have a maximum supply voltage of 3.6V, so they can only output 5V levels if the respective pin is able and set to operate as an open drain, without internal pull resistors and with external pull-up to 5V.

Does it answer your question?

Regards

/Peter

[Kmax18]

Thank you @Peter BENSCH​ . Yes that answers my question.