CURRENT SENSING OF EMITTER SENSE INSULATED-GATE BIPOLAR TRANSISTOR (IGBT)

摘要

A control circuit and method are disclosed for controlling a current sense Insulated-Gate Bipolar Transistor (IGBT). In particular, the current sense IGBT creates voltage spikes in a sense voltage as a result of normal switching operations. The control circuit creates a blank period so that the voltage spikes are ignored and false detections of short-circuit events are avoided.

主权项

1. A circuit adapted to sense one or more currents output by an Insulated-Gate Bipolar Transistor (IGBT), wherein the one or more currents output by the IGBT include a sense current and an emitter current, wherein the sense current corresponds to a fractional value of the emitter current, wherein the sense current flows through a sense resistor, thereby creating a sense voltage, the circuit comprising:
a blank circuit that creates a blank period for a voltage being monitored in connection with the sense voltage, wherein the blank period blanks out noise spikes created in the sense voltage by transients created in the IGBT during normal switching of the IGBT; and a filter circuit that enables the voltage being monitored in connection with the sense voltage to at least track the sense voltage after the blank period has ended.