A sic MOSFET gate auxiliary circuit

Abstract

The invention discloses an SiC (Silicon Carbide) MOSFET (Metal Oxide Semiconductor Field Effect Transistor) gate electrode auxiliary circuit. The SiC MOSFET gate electrode auxiliary circuit comprisesa grid source circuit and a bypass branch circuit, wherein the grid source circuit comprises a grid electrode resistor, a voltage source unit and a serial resistor, which are serially connected between a gate electrode of an SiC MOSFET and a source electrode in sequence; the voltage source unit comprises two direct-current voltage sources which are in inverse parallel; each direct-current voltagesource is connected with a control switch in series; the bypass branch circuit comprises an auxiliary capacitor and a triode unit, which are connected in series; the triode unit comprises two triodeswhich are in inverse parallel; one end of the auxiliary capacitor is one end of the bypass branch circuit and is connected onto a connection line of the gate electrode of the SiC MOSFET and the grid source circuit; collection electrodes of the two triodes are connected to the other end of the auxiliary capacitor; a base electrode of each triode is connected with an emitting electrode of each triode; the respectively connected base electrodes and emitting electrodes of the two triodes are connected to two ends of the serial resistor respectively. According to the SiC MOSFET gate electrode auxiliary circuit, serial disturbance can be inhibited and the switching-off speed of a device is ensured.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a SiC MOSFET gate auxiliary circuit applicable to series disturbance suppression. Background technique [0002] Wide-bandgap semiconductors led by silicon carbide (Silicon Carbide, SiC) MOSFETs have faster turn-off speeds, higher forward withstand voltages, lower heat dissipation requirements, and have certain reverse withstand voltage capabilities (the first The first-generation SiC MOSFET can withstand -5V, and the second-generation SiC MOSFET can withstand-10V), which has broad prospects in some occasions that require high-density power. However, with the higher switching speed, the parasitic parameters in the original circuit become more sensitive. Although the new PCB manufacturing process and packaging technology can effectively reduce the size of the parasitic parameters, SiC MOSFETs still face the problem of series connection. risk of disturbance. [0003] At ...

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Problems solved by technology

Some literature proposes an RCD level shifter, which uses resistor series circuit voltage division and capacitor energy storage to provide C gs Provide negative pressure, but it will inevitably reduce the breaking frequency and increase the breaking loss when the capacitor is charged and discharged

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