Gate drive circuit having reduced current-consumption and rapid inductive energy dissipation

摘要

A gate drive circuit device for a voltage-driven semiconductor element reduces the time to dissipate inductively stored electromagnetic energy and reduces current consumption by using cyclically charged capacitative storage to produce a control signal that is about twice the supply voltage. This permits full-ON dissipation of the stored energy after the circuit cuts off power to the inductive element. In one embodiment, the dissipation is chiefly in a voltage-regulator diode connected to limit the voltage appearing across a transistor. In another embodiment, a voltage regulator diode permits a transistor to operate in the full-on condition, while limiting the voltage across it to a value below its withstand voltage, whereby a maximum power dissipation current flows in the transistor. In a further embodiment a gate drive signal generator eliminates a voltage regulator diode from the conventional gate drive circuit device. Instead, this embodiment substitutes switching devices both on the power supply side and the reference potential (ground) side. Both switching devices include a switch and an operating section that controls switching operation. The two operating sections receive an externally generated command signal for timing the ON/OFF operation of the switches. The control technique permits both the switching and operating sections to be fabricated integrally as an integrated circuit.