Tool/software:
Hello,
I'm designing a current sense circuit for an application that have some very high peaks as well as long periods of low current. It is important for performance to measure the low current very accurately and important for safety to be able to measure high peak currents. I would like to use two separate channels on my micro as current sensor inputs. The idea is to have a very high gain current sense amplifier that would intentionally rail when there is around 20A flowing through my shunt, at which point the micro would switch over to reading the second current sensor channel which would have a lower gain and be able to read up to 200A. The limiting factor pushing me towards this design is limited resolution on my micro's ADCs.
I think this should be okay, but a couple of lines in the manual are giving me pause. I'm not sure how differently these current sense amplifiers behave from a standard Op-amp. The highest voltage the analog input would see is about +-80mV, so very far bellow the max input. But with a gain of 200v/v will I run into any issues with exceeding the output voltage? or will the output just rail at the supply voltage of 5V?
Thanks,
Patrick