Hi all,
I want to use an external reference voltage on the Vref pin but this is a problem because the powerup of the main Vdda regulator is different of the reference voltage regulator (one starts before the other), in the worst case one can give 3.3V while the other hasn't started yet giving zero volts, this situation only lasts a few milliseconds but enough to damage something.
In the STM32F427 manual only appears that VDDA-VREF < 1.2 V, this means that if on powerup Vdda = 3.3 while Vref is starting and it's only 1V the device will me damaged? Or Vref should start before VDDA?.. this sounds rare.
I've damaged devices is the past for not respecting this (STM32F373 have a very very special power up secuence because the Sigma Delta ADC).
Thanks
