Control circuit and method as well as power supply device

Abstract

The invention provides a control circuit and method as well as a power supply device. The control circuit comprises an acquisition module, a maintaining module and a control module, wherein the acquisition module is used for obtaining a voltage signal generated by reversed surge current when the reversed surge current occurs on a primary edge of a switching power supply circuit of a synchronous rectification circuit; the maintaining module is used for continuously outputting a first control signal in a preset first time period when the voltage signal is greater than a preset first voltage threshold value; the control module is used for controlling and switching off a secondary edge switching pipe of the switching power supply circuit of the synchronous rectification circuit according to the first control signal. With the adoption of the technical scheme of the embodiment of the invention, the current reversed surge in the switching power supply circuit of the synchronous rectification circuit can be effectively inhibited and the safety of the switching power supply of the synchronous rectification circuit can be effectively protected. According to the power supply device adopting the control circuit, the safety and the reliability of the power supply can be effectively improved.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of power supplies, and in particular, to a control circuit and method, and a power supply device. Background technique [0002] In the field of power technology, synchronous rectification circuit is a very widely used circuit. [0003] The switching power supply circuit of the traditional synchronous rectification circuit generally uses a diode to realize rectification, but the conduction loss of the diode is relatively high, resulting in low working efficiency of the switching power supply using the diode rectification circuit. Later, metal-oxide-semiconductor field-effect-transistor (Metal-Oxide-Semiconductor Field-Effect-Transistor; hereinafter referred to as MOSFET or MOS transistor) and other switching tubes were gradually used to replace traditional diodes to achieve synchronous rectification. Such as figure 1 Shown is the circuit diagram of the switching power supply circuit of...

AI Technical Summary

Problems solved by technology

[0006] The embodiment of the present invention provides a control circuit and method, and a power supply device, which are used to solve the defect that the circuit for preventing current reverse surge in the prior art increases system cost and power consumption, and can reduce the cost and power consumption without increasing the cost and power consumption. , effectively achieve reverse current surge suppression

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