Hi,
I have a microcontroller circuit and I use 5V regulator (RECOM) and another 3.3v regulator (LM1085, 3.3) for a finger print sensor.
In some unknown situation, the sensor gets destroyed.

I am using a good SMPS for 230VAC to 12VDC, which goes to RECOM 12V to 5V and then 5V to 3.3V.

Is this because of the capacitor(10uF/25) at the output of 3.3v regulator which has 25V rating? I am thinking in that way because the sensor is so sensitive.
Or is it because of any negative current ?

Is there any solution to avoid this problem using any current/ or voltage limiter?

Thanks n rgrds
Jaison

 

I think we will need a schematic of the circuit to get to the bottom of your problem in a timely manner.

hgmjr

 

Do you have the part number of the finger print sensor that you are using?