Circuit for driving SiC MOSFET

Abstract

The invention belongs to the technical field of circuit control, and particularly relates to a circuit for driving a SiC MOSFET. The circuit comprises a switching power supply module, a logic controlmodule and a driving and protecting module; in the switching power supply module, a switching frequency generation circuit and a feedback circuit are built in a driving chip U1; the switching power supply module is used for receiving an external input voltage, and outputting an unconventional voltage required to drive the SiC MOSFET; the logic control module is used for completing setting and state monitoring on the driving chip U1 in the switching power supply module; and the driving and protecting module is used for driving the SiC MOSFET and protecting the driving chip U1 and the SiC MOSFET. According to the circuit, the switching frequency generation circuit and the feedback circuit are built in the driving chip, so the distribution interference is greatly reduced, and the circuit structure is simple; and thus, the cost is reduced, the reliability is improved and the false switching of the SiC MOSFET is inhibited.

Description

technical field [0001] The invention belongs to the technical field of circuit control, and in particular relates to a SiC MOSFET driving circuit. Background technique [0002] As a new type of material, SiC material has excellent physical and chemical properties such as large band gap, high breakdown voltage, and high thermal conductivity. By using power devices made of SiC materials, people can greatly increase the switching speed of the device and reduce the device. power consumption, reducing the size of the device. SiC MOSFET, as the current mainstream power device of SiC material, has received extensive attention in the field of power electronics. [0003] However, the gate threshold voltage of SiC MOSFET is lower than that of ordinary Si MOSFET, usually only about 2V, and it is easier to turn on. In the case of external disturbance signals, it is easy to turn on by mistake; on the other hand, the normal operating voltage of SiC MOSFET is at 18V ~20V, the normal work...

AI Technical Summary

Problems solved by technology

[0005] The negative voltage required for SiC MOSFET driving is realized by adding a first-stage conversion circuit on the basis of the conventional voltage. The power supply structure is complex, especially in the case of isolated multi-channel drive, not only the circuit structure is complicated, but also the cost is high.

[0006] It is an economical solution to realize negative voltage by using switching power supply to output multiple voltages, but the realization of switching power supply circuit itself requires more discrete components, and too many discrete components will inevitably increase some distributed interference, which will have a negative impact on SiC MOSFET causes false turn-on, which is not conducive to the driving of SiC MOSFET, especially in the switching power supply circuit, the key circuits such as switching frequency generation circuit and feedback circuit are greatly affected by the external circuit environment, and the stability and reliability cannot be fully guaranteed. , this type of switching power supply is not suitable as a driving power supply for SiC MOSFET

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