SiC MOSFET short circuit protection circuit

Abstract

The invention discloses a SiC MOSFET short-circuit protection circuit, which comprises a peak value acquisition module, a short-circuit monitoring module and an isolation and latch module, and is characterized in that the peak value acquisition module monitors voltage fluctuation on a source parasitic inductor of a SiC MOSFET to trigger the short-circuit monitoring module to start working; the short circuit monitoring module judges whether short circuit occurs and outputs short circuit fault signals, the isolation and latch module is responsible for isolating and latching various signals, through the structure, the protection action can be quickly realized, meanwhile, different types of short circuit faults can be accurately monitored and identified, the number of used elements is small, and the cost is low. Low cost is ensured, and the circuit can be easily integrated in a driving circuit for practical application.

Description

technical field [0001] The invention relates to the field of short circuit protection of power semiconductor devices, in particular to a SiC MOSFET short circuit protection circuit for TO-247-4 package or power module. Background technique [0002] With the popularization of wide bandgap power semiconductor devices in engineering applications, SiC MOSFET devices gradually replace the market share of IGBTs in industrial automation, consumer electronics and new energy fields due to their high switching speed, high power density and low loss. However, the fragile gate structure of SiC MOSFET makes it less reliable than IGBT in the face of short-circuit faults. Relevant studies have also shown that the short-circuit withstand time of SiC MOSFET is much shorter than that of IGBT. [0003] There are a variety of short-circuit protection methods developed for IGBT devices. The overall characteristic of this type of method is that it takes a long time to identify and act on short-ci...

AI Technical Summary

Problems solved by technology

However, the fragile gate structure of SiC MOSFET makes it less reliable than IGBT in the face of short-circuit faults. Relevant studies have also shown that the short-circuit withstand time of SiC MOSFET is much shorter than that of IGBT.

[0003] There are a variety of short-circuit protection methods developed for IGBT devices. The overall characteristic of this type of method is that it takes a long time to identify and act on short-circuit faults. Compared with the short-circuit withstand time of SiC MOSFETs, they cannot protect SiC MOSFETs in time. To protect the effect, and the actual short-circuit fault is also divided into hard switching fault (bridge arm through) and load short-circuit (phase-to-phase short-circuit) fault, the protection effect of some methods is affected by the type of short-circuit fault, that is to say, not two short-circuit faults Both can trigger the short-circuit protection action, thereby laying hidden dangers for the safe operation of the equipment. In addition, the faster switching speed of SiC MOSFET may also bring the risk of false triggering for this short-circuit protection method.

Images