Improved gate drive device for SiC MOSFET bridge crosstalk suppression

Abstract

The invention relates to an improved gate drive device for SiC MOSFET bridge crosstalk suppression, belonging to the technical field of SiC driving. The device includes a main drive circuit and a passive auxiliary circuit, the main drive circuit is composed of a DC-DC converter unit, an optocoupler isolation chip unit, a drive chip unit and a drive resistor unit, and the passive auxiliary circuit is composed of a forward peak voltage suppression unit and an inverse peak voltage suppression unit. The invention provides a novel auxiliary circuit improved driving method additionally provided with a triode serial capacitor on the basis of a conventional drive circuit. Through the reasonable design of the main drive circuit and the passive auxiliary circuit, the aims of bridge crosstalk suppression, switch time-delay time shortening, switch loss reduction, and control complexity reduction can be achieved. The device provided improves the work reliability and efficiency of a SiC MOSFET bridge converter and reduces the cost and complexity of drive control.

Description

technical field [0001] The invention belongs to the technical field of SiC MOSFET drive design and relates to an improved gate drive device for suppressing crosstalk of SiC MOSFET bridge arms. Background technique [0002] In recent years, wide bandgap semiconductor devices represented by silicon carbide (Silicon Carbide, SiC) MOSFETs have become a high Ideal device choice for high frequency, high temperature, high power density drives. However, in the bridge converter, the high switching speed characteristic of SiC MOSFET increases the switching frequency, reduces the switching loss, and shortens the dead time. At the same time, it is affected by the parasitic parameters of the device, which will cause a rapid disconnection of a device in the bridge circuit. A crosstalk phenomenon that causes oscillations in the gate-to-source voltage of another complementary device. Since the positive threshold voltage and the maximum turn-off negative voltage of SiC MOSFET are small, th...

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Problems solved by technology

At present, the commonly used suppression method of increasing the driving resistance and parallel capacitance prolongs the switching delay time and increases the switching loss; while the suppression method of controlling the driving impedance by monitoring the Miller plateau period is effective in accurately monitoring the state of the switch. It is difficult; the suppression method of negative pressure shutdown reduces the negative pressure margin, which is easy to cause negative pressure overlimit; while the suppression method of active clamp requires an external control signal, which increases the control cost and complexity

Therefore, on the premise of not prolonging the switching delay time, not increasing the switching loss and the control complexity, a simple and effective suppression method is urgently needed to solve the bridge arm crosstalk problem in the SiC MOSFET driving process.

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