Comparator as a current detector
TC75S58' spec
- common mode input voltage range : VSS to VDD− 0.9 V . 

So this IC as a high side current detector will not work.
But you might use it on the low side.  (Or find a high side Comparator.)

Choose shunt R to read 50mV at full scale. ( most common) 







simulate this circuit &ndash; Schematic created using CircuitLab

You must be careful on matched R tolerances, input offset since the current sense is very low mV    

THis puts the high side in the acceptable CM range.


There are many advantages to low side sensing  .