Half-bridge driving circuit

Abstract

The invention discloses a half-bridge driving circuit which comprises a bootstrap circuit and a half-bridge circuit, and further comprises a first switch circuit, a second switch circuit, a first discharge circuit and a second discharge circuit, wherein the bootstrap circuit comprises a diode and a capacitor; the first switch circuit is powered on when a first control signal is in high level and is powered off in low level; the second switch circuit is powered on when a second control signal is in low level and is powered off in high level; the first discharge circuit is powered off when the first switch circuit is powered on and is powered on when the first switch circuit is powered off; the second discharge circuit is powered on when the second control signal is in high level and is powered off in low level; the on / off states of the two switch circuits are changed by changing the input control signals so as to control the on / off of upper and lower bridges; when the first discharge circuit is powered on, a control end of the upper bridge can be controlled to discharge electricity so as to accelerate the upper bridge to be closed; when the second discharge circuit is powered on, a control end of the lower bridge can be controlled to discharge electricity so as to accelerate the lower bridge to be closed. The electricity discharge speeds of the control ends of the upper bridge and the lower bridge are respectively accelerated through the first discharge circuit and the second discharge circuit.

Description

technical field [0001] The invention relates to a driving circuit of a switching power supply, in particular to a half-bridge driving circuit. Background technique [0002] Switching power supply is a kind of power supply that uses modern power electronic technology to control the time ratio of switching on and off to maintain a stable output voltage. It has a series of advantages such as small size and high efficiency, and is widely used in various electronic products. In a high-power switching power supply, it is necessary to use a half-bridge drive circuit to drive the half-bridge circuit, but the driving of the high-end side of the half-bridge drive circuit requires high voltage to achieve, so generally an integrated circuit with a bootstrap function is used as the half-bridge Drive circuit. [0003] A half-bridge circuit is usually realized by two semiconductor field effect transistors (MOSFETs) or insulated gate bipolar transistors (IGBTs), where the drain (or collect...

AI Technical Summary

Problems solved by technology

[0006] Based on this, it is necessary to provide a half-bridge drive circuit that accelerates the discharge speed in view of the problem that the traditional half-bridge drive circuit discharges the control terminals of the upper and lower bridges at a slower rate.

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