Switch MOS (metal oxide semiconductor) bootstrap charge circuit applicable to gate drive of high-speed GaN power devices

Abstract

A switch MOS (metal oxide semiconductor) bootstrap charge circuit applicable to gate drive of high-speed GaN power devices belongs to the technical field of electronic circuitry and comprises an inverter chain, a diode, a charge pump capacitor and a switch tube; the output end of the inverter chain is connected with a cathode of the diode through the charge pump capacitor; an anode of the diode isconnected with power supply voltage; a gate of the switch tube is connected with the cathode of the diode, and a drain of the switch tube is used as an output end of the switch MOS bootstrap charge circuit. The switch MOS bootstrap charge circuit also comprises a level shift module, a constant-current source module and a switch module; the input end of the level shift module is used as the inputend of the switch MOS bootstrap charge circuit, and the output end of the level shift module is connected with the input end of the inverter chain; the constant-current source module is connected between the gate and ground of the switch tube; the switch module is connected between the source of the switch tube and the power supply voltage. The problem can be solved that a traditional switch MOS bootstrap circuit experiences mistaken opening of a switch tube and overcharging of a bootstrap capacitor.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and relates to a bootstrap circuit suitable for high-speed driving circuits, in particular to a switching MOS bootstrap charging circuit suitable for gate driving of high-speed GaN power devices. Background technique [0002] In a BUCK converter, a drive circuit is usually required to control the upper and lower power transistors to turn on. During the turn-on process of the lower power transistor, the switch node SW is pulled down to the ground potential VSS; while in the turn-on process of the upper power transistor, the potential at the switch node SW is gradually pulled up to the input level VIN, thus, the potential at the switch node SW is It floats between the input level VIN and the ground potential VSS. In the gate drive circuit where the upper power transistor is NMOS, the source potential of the upper power transistor is the potential at the switch node SW, so the gate of t...

AI Technical Summary

Problems solved by technology

[0011] Aiming at the problems of unstable gate voltage of the switching tube MN10 and overcharging of the bootstrap capacitor Cboot existing in the above-mentioned traditional switching MOS bootstrap circuit, the present invention proposes a switching MOS bootstrap charging circuit, which can be applied to high-speed GaN power devices. The gate drive circuit is used to solve the problems of wrong turn-on of the switch tube MN10 and overcharging of the bootstrap capacitor Cboot

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