STM32L451 and PC13/14/15 in SHUTDOWN Mode

[N.F. Singh]

Documentation is a bit vague with respect to use of PC13/14/15 as GPIO while MCU is in SHUTDOWN mode. My understanding is that these pins can be used in the backup domain (my VBAT is connected directly to VDD).

I understand that I could SINK up to 3mA. I also understand I cannot SOURCE current from them, per se.

However, what I would like to do is use these outputs in push-pull mode and use them to "drive" two small-signal MOSFET gates (combined capacitance of 24.6pF).

Am I correct in assuming this is possible in SHUTDOWN mode? No gotchas?

Thanks,

Nicholas

  

[Uwe Bonnes]

I my understanding you can sink current on PC13-15 like on any other pin The switch may only deliver 3 mA as source in total and transient currents need to be considered. I alsoe would assume that in Shutdown the switch is still in the VDD position, versus in the VBat position with VDD < VDD min..But I do not find that documented.

[N.F. Singh]

Thanks for the reply. It says right there in my copy/paste that when the VBAT is supplied by VDD, the backup domain allows use of PC13/14/15 as general GPIO.

And per the document I don't think you can SOURCE current from those pins. Only sink.

But my question still remains about being able to "drive" some MOSFET gates. That's not really using the pins as a current source... but I just want to make sure.