Hello,
for my application I need to connect a signal to the AIO0 input of the AT3 module. This signal is referenced to ground of the module and can go as high as 1.8V before the regulator can switch the module on and supply VCC with 3.3V - clearly out of spec. This condition is present for max. 30ms at each powering-up. Since I have a harvester, there is not much I can do about the delay of the regulator. It needs the input capacitor charged first.
My questions:
What would be a suitable input protection for AIO0?
Is there any documentation about the input (equivalent) circuit such that I can set up a model for it?
A simple series resistor could be used to limit the input current to less than 2mA. Would that do the job?
Thank you.
Regards,
Heinrich