INSULATED GATE DEVICE DISCHARGING

摘要

A large-power insulated gate switching device (e.g., MOSFET) is used for driving relatively large surges of pulsed power through a load. The switching device has a relatively large gate capacitance which is difficult to quickly discharge. A gate charging and discharging circuit is provided having a bipolar junction transistor (BJT) configured to apply a charging voltage to charge the gate of the switching device where the BJT is configured to also discontinue the application of the charging voltage. An inductive circuit having an inductor is also provided. The inductive circuit is coupled to the gate of the switching device and further coupled to receive the charging voltage such that application of the charging voltage to the inductive circuit is with a polarity that induces a first current to flow through the inductor in a direction corresponding to charge moving away from the gate and such that discontinuation of the application of the charging voltage to the inductive circuit induces a second current flowing through the inductor in the direction corresponding to charge moving away from the gate such that the second current discharges the gate of the switching device. Faster turn off of the switching device is thus made possible and is synchronized to the discontinuation of the charging voltage.

主权项

1. A method of charging and discharging a gate of an insulated gate switching device comprising:
applying a charging voltage to charge the gate of the switching device; at substantially a same time applying the charging voltage to an inductive circuit having an inductance, the inductive circuit being coupled to the gate, the applying of the charging voltage to the inductive circuit being with a polarity that induces a first current to flow through the inductance in a direction corresponding to charge moving away from the gate; and discontinuing the applying of the charging voltage to the inductive circuit; wherein the discontinuing of the applying of the charging voltage to the inductive circuit induces a second current to flow through the inductance in the direction corresponding to charge moving away from the gate, the second current discharging the gate of the switching device.