Bidirectional current sensing for power MOSFETS.

摘要

A circuit capable of being integrated into a self-isolated DMOST is driven by a sense resistor that is created from the DMOST drain metallization. The circuit produces an output current that is ratioed with respect to the DMOST current with the ratio being determined by the value of a single resistor. The output current is sourced when the DMOST conducts its source current and the output current is sunk when the DMOST shunt diode conducts. Thus, the circuit not only produces a DMOST current related output it also distinguishes the mode of DMOST conduction.