2021-04-11 04:10 PM
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
2021-04-13 11:37 AM
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.
2021-04-13 04:58 PM
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.