Multi-stage step-down gate voltage type sic-mosfet drive circuit

Abstract

The invention discloses a multi-stage grid voltage reduction SiC-MOSFET drive circuit, including a short-circuit detection circuit, a turn-off logic control circuit, a totem pole circuit, a first-stage grid voltage reduction circuit, and a second gate voltage reduction soft-off circuit The short-circuit detection circuit judges the short-circuit peak current to detect the real occurrence of a short-circuit fault, and the first-stage gate voltage reduction circuit reduces and maintains the SiC-MOSFET gate voltage to the maximum short-circuit withstand time, improving the short-circuit ride-through capability of the device; through the second-stage reduction The gate voltage circuit further reduces the gate voltage to achieve soft turn-off, thereby suppressing the turn-off voltage spike. The invention ensures that the SiC-MOSFET is safely turned off under short-circuit conditions, effectively increases its short-circuit withstand time, and improves the fault ride-through capability.

Description

technical field [0001] The invention belongs to the field of power semiconductor devices, and in particular relates to a multi-stage gate voltage reduction SiC-MOSFET driving circuit. Background technique [0002] With the market's increasing demand for high-efficiency, high-power-density converters, such as the rise of new energy and electric vehicles, wide bandgap devices SiC-MOSFET (silicon carbide-metal oxide semiconductor field-effect transistor) are gradually being used. Compared with traditional Si-based power devices, SiC-MOSFET has weak short-circuit tolerance and is greatly affected by working conditions. When SiC-MOSFET works under conditions such as high DC bus voltage and high ambient temperature, its short-circuit tolerance will be limited significantly weakened. At the same time, in order to achieve fast turn-on and turn-off to reduce switching loss and reduce on-resistance to reduce conduction loss, the driving positive voltage of SiC-MOSFET is usually maint...

AI Technical Summary

Problems solved by technology

This method prolongs the short-circuit withstand time, but does not make full use of the short-circuit withstand capability of the device, and cannot achieve short-circuit fault ride-through

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