Synchronous rectification switching tube driving method and device of phase-shifted full-bridge circuit

Abstract

The invention discloses a synchronous rectification switching tube driving method of a phase-shifted full-bridge circuit. The method is used for providing driving signals for a lead bridge arm switching tube and vice-side synchronous rectification switching tubes of the phase-shifted full-bridge circuit. The method includes that driving signals of four primary side power switches of the phase-shifted full-bridge circuit are received and subjected to logic conversion to obtain primary driving signals of two vice-side synchronous rectification switching tubes; output current is sampled, sequences of a power switch of a primary side full-bridge circuit lead arm are adjusted, or the phase-shifted full-bridge circuit is subjected to synchronous rectification when sequences of two vice-side synchronous rectification switching tubes are adjusted. The invention further discloses a synchronous rectification switching tube driving device of the phase-shifted full-bridge circuit. By means of the synchronous rectification switching tube driving method, a soft-switching technology in a full load range of the phase-shifted full-bridge circuit can be achieved, and purposes for reducing light load loss and improving efficiencies are achieved.

Description

technical field [0001] The invention relates to the technical field of phase-shifted full-bridge soft switches, in particular to a method and device for driving a synchronous rectification switching tube of a phase-shifted full-bridge circuit. Background technique [0002] At present, switching power supplies are developing towards high power density and high efficiency, and the phase-shifted full-bridge topology is being used more and more because of its excellent soft switching characteristics. The secondary synchronous rectification technology of the phase-shifted full-bridge circuit also replaces the traditional diode rectification in the application of outputting low voltage and high current. [0003] However, in the prior art, for the phase-shifted full-bridge circuit, whether it is diode rectification or synchronous rectification using MOSFET, there is an obvious shortcoming: at light load, the switching tube on the lagging arm is difficult to achieve soft switching, ...

AI Technical Summary

Problems solved by technology

[0003] However, in the prior art, for the phase-shifted full-bridge circuit, whether it is diode rectification or synchronous rectification using MOSFET, there is an obvious shortcoming: at light load, the switching tube on the lagging arm is difficult to achieve soft switching, resulting in its Excessive losses at light load

Therefore, it also limits the application of phase-shifted full-bridge circuits in server power supplies that require high efficiency when the load is light-loaded.

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