With the growth of Hybrid Electric vehicles (HEV) and Electric vehicles (EV), the conventional 12V circuits now need to communicate with higher voltage circuits. For the hybrid vehicles, this would be 48V batteries whereas for the fully electric vehicles this could be 400V or even more.
These multiple voltage domains in the car make it mandatory to include isolation devices to protect the low voltage side components and circuits from the high voltage battery side. This adds a new challenge to the designers who were not used to isolation in the conventional vehicles. This document provides various options to isolate the ADC's in battery monitoring circuits.