Patent ID: 7005881

Claim:
A circuit for sensing the current through a power MOSFET in both the linear and saturated regions of operation of the power MOSFET comprising: a first circuit coupled to the power MOSFET for sensing the current through the power MOSFET in the saturated region of operation of the power MOSFET; and a second circuit coupled to the power MOSFET for sensing the current through the MOSFET in the MOSFET's linear region of operation, wherein the second circuit comprises a resistance coupled in series with the current sense cell, and a current mirror coupled to the resistance providing a current mirror output, whereby a current provided by the current mirror output is proportional to the current through the current sense cell, and further comprising an amplifier coupled to the current mirror output and coupled to a reference voltage, the amplifier producing an output proportional to the current from the current mirror and proportional to the current in the main cell of the power MOSFET.