Patent ID: 7327149

Claim:
A current sensing circuit comprising: a power device adapted to conduct a bidirectional current between first and second terminals thereof; a first sensing device operatively coupled to the first terminal of the power device and a second sensing device operatively coupled to the second terminal of the power device, the first and second sensing devices each having an active area that is substantially identical and significantly smaller than a corresponding active area of the power device, the first and second sensing devices providing respective first and second voltages; a sense amplifier operatively coupled to the first and second sensing devices, the sense amplifier measuring the first and second voltages and injecting current to the second sensing device in order to maintain the first and second voltages equal to each other, the sense amplifier further providing an output current proportional to the bidirectional current; and a gate drive device operatively coupled to activation terminals of the power device and the first and second sensing devices, the gate drive device providing activation signals to the power device and the first and second sensing devices.