Electrification of the  car has mandated the use of high-power devices — notably batteries,  inverters, and regenerative braking systems — whose interfacing with  digital control circuits requires the adoption of appropriate galvanic  isolation techniques.

In short, galvanic isolation means an electrical separation between two circuits, which occurs when the insulation resistance that separates them is infinite or very high: There is no electrical connection 

between the two circuits.

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