Half-bridge drive circuit

Abstract

The invention relates to a half-bridge drive circuit comprising a half-bridge circuit, a driver and a bootstrap capacitor charging circuit, wherein the half-bridge circuit is connected between a power supply VBAT (Voltage of Battery) and a power ground GND (Ground); a signal input end of the driver is connected with an external control unit; a high-side driving signal output end, a high-side driving floating ground end, a low-side driving signal output end and a low-side driving ground end on a driver are connected with the half-bridge circuit; and the bootstrap capacitor charging circuit is simultaneously connected with a high-side driving floating power supply end and the high-side driving floating ground end on the driver, and the bootstrap capacitor charging circuit and the driver share low-voltage input. The half-bridge drive circuit is characterized by further comprising a charging pump circuit which is used for maintaining the voltages on two ends of a charging capacitor C1 when a low-voltage input end cannot charge the charging capacitor C1 through a diode D1 in the bootstrap capacitor charging circuit, the charging pump circuit is connected with the high-side driving floating power supply end and the high-side driving floating ground end on the driver, and the ground of the charging pump circuit is connected with the power ground of the half-bridge circuit. The half-bridge drive circuit has the adaptability to a wide working condition range and is suitable for driving various half-bridge circuits in the technical field of power electronics.

Description

technical field [0001] The invention relates to a driving circuit, in particular to a half-bridge driving circuit. Background technique [0002] Metal-oxide-semiconductor field-effect transistors (MOSFETs) and insulated-gate bipolar transistors (IGBTs), as high-speed switching devices, have been widely used in power electronics. In practical applications, transistors are often used to form a half-bridge circuit, in which the drain (or collector) of the upper bridge transistor is connected to the power supply, and the source (or emitter) is connected to the drain (or collector) of the lower bridge transistor. The source (or emitter) of the lower bridge transistor is connected to the power ground, and the output terminal of the half bridge circuit is the common terminal of the upper and lower bridge transistors. The half-bridge circuit performs corresponding switching actions according to a PWM signal output by an external control unit (such as a microprocessor). But the sig...

AI Technical Summary

Problems solved by technology

In this case, the low-voltage input terminal (pin VDRV) cannot charge the charging capacitor C1 through the diode D1, the driver 2 cannot start, and the half-bridge circuit 1 cannot work normally.

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