WKUP Pin versus Analog Input 0

431613 · ‎2016-08-05

Posted on August 05, 2016 at 14:08

Hi everyone,

I have a STM32f105RC implementation where i use the analog pin 0 as an analog input. During some ESD tests, I had some problems with a resetting MCU. Im searching for some pins, which can be a possible path for the ESD pulse (15kV air). There are possibilities for this ESD to get through the circuit onto this analog pin (there are some diodes and resistors in between, but one can be sure that a voltage will appear as a consequence of an ESD).

I have a concern about this WKUP feature and i'm not pretty sure about its function. The pin is initialized as an analog input. Now my question:

Is it possible, that a rising (or falling) edge (caused by an ESD event) on this analog pin toggles the wkup mode and causes a reset? Or is it impossible to trigger the WKUP pin, if I initialize this pin as an analog input? Would an incoming edge on this pin trigger a reset?

Thanks a lot for your opinions and answers,

regards,

marc

#!stm32-!wkup-!analog-input

waclawek.jan · ‎2016-08-05

Posted on August 05, 2016 at 20:04

>. During some ESD tests, I had some problems with a resetting MCU.

I'd start with qualifying the source of the reset in RCC_CSR.

I'd also look at the integrity of analog supply and ground.

JW