Patent ID: 6998800

Claim:
A system for sensing one or more motor currents from a three phase inverter, comprising: a first sense resistor coupled between a first switch of a first leg of a three phase inverter and a supply voltage and adapted to sense a first motor current when the first switch is active; a second sense resistor coupled between a second switch of the first leg of the three phase converter and ground and adapted to sense the first motor current when the second switch is active; and a first circuitry adapted to: generate an upper current that is proportional to the difference of a first reference voltage and a voltage across the first sense resistor when the first switch is active, and proportional to the first reference voltage when the first switch is inactive; generate a lower current that is proportional to the sum of a second reference voltage and a voltage across the second sense resistor when the second switch is active, and proportional to the second reference voltage when the second switch is inactive, wherein the second reference voltage is essentially the same as the first reference voltage; and provide a first output current that is essentially the difference of the lower current and the upper current, thereby providing a first continuous output current that is proportional to the first motor current provided by the three phase inverter.