Drive control circuit for shunt-wound synchronous rectification tubes and switching power supply

Abstract

The invention discloses a drive control circuit for shunt-wound synchronous rectification tubes, which is used for driving and controlling the N shunt-wound synchronous rectification tubes, wherein N is a positive integer. The drive control circuit has an input end and M output ends, wherein the input end is used for acquiring a load current signal; the M output ends are used for outputting driving signals; M is the positive integer more than or equal to N; the M output ends are connected with drive electrodes of the N synchronous rectification tubes; the drive electrode of each synchronous rectification tube is connected with one output end; each output end is connected with the drive electrode of at least one synchronous rectification tube; and the drive control circuit controls the number of switched-on synchronous rectification tubes of the N shunt-wound synchronous rectification tubes according to the magnitude of the load current signal. The embodiment of the invention also provides a corresponding switching power supply. The drive control circuit provided by the embodiment of the invention can adaptively adjust the number of the switched-on synchronous rectification tubes according to the change of a load, thereby satisfying application needs, reducing the drive loss under low-load condition and improve light load efficiency.

Description

technical field [0001] The invention relates to the technical field of synchronous rectification, in particular to a drive control circuit and a switching power supply of parallel synchronous rectification tubes. Background technique [0002] Synchronous rectification (Synchronous Rectification, SR) technology is widely used in switching power supplies to improve the efficiency of switching power supplies. Synchronous rectification technology replaces rectifier diodes to reduce rectification conduction losses by using special power Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) with extremely low on-state resistance as synchronous rectifier tubes. In order to meet the application scenarios of high power and high current and reduce losses, the application of synchronous rectifier tubes in parallel has appeared. figure 1 It is a schematic diagram of parallel connection of three synchronous rectifiers. [0003] Please refer to figure 2 , when the existing sync...

AI Technical Summary

Problems solved by technology

Therefore, switching power supplies have large driving losses and low efficiency in application scenarios with small loads, and cannot achieve efficiency optimization for load conditions.

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