Topology circuit of wide-range input voltage isolation type switch power supply and control method of topology circuit

Abstract

The invention relates to a topology circuit of a wide-range input voltage isolation type switch power supply and a control method of the topology circuit. The topology circuit comprises push-pull circuit, a rectifying and filter circuit and a synchronous rectifying BUCK circuit, wherein the push-pull circuit comprises a transformer and VMOS tubes; two ends of the primary winding of the transformer are respectively connected with the drains of the first VMOS tube and the second VMOS tube, the central contact of the primary winding of the transformer is externally connected with a power supply input loop, the grids of the first VMOS tube and the second VMOS tube are connected with the control circuit of the switch power supply, the sources of the first VMOS tube and the second VMOS tube are grounded, and two ends of the secondary winding of the transformer are respectively connected with the synchronous rectifying tube and the output public end of the synchronous rectifying BUCK circuit through the rectifying and filter circuit. The topology circuit has the advantages that isolation and efficient features of push-pull topology are utilized, isolation pre-stabilization of the wide-range input voltage is achieved, the design of a multi-path low-voltage-output circuit is simplified, overall circuit efficiency is increased, and size is reduced.

Description

technical field [0001] The invention relates to the technical field of switching power supplies, in particular to a topology circuit of a wide input voltage isolated switching power supply and a control method thereof. Background technique [0002] Switching power supplies are widely used in the fields of industry and national defense, and are widely used in military and civilian electronic systems such as aerospace, aviation, ships, weapons, railways, communications, medical electronics, and industrial automation equipment. Switching power supply has developed rapidly since its invention. New application requirements are constantly emerging along with new technologies. To sum up, there are dozens of commonly used circuit topologies, such as BUCK circuit, BOOST circuit, forward circuit, flyback circuit, push-pull circuit, half-bridge circuit, full-bridge circuit topology, etc. BUCK circuit and BOOST circuit are commonly used circuit topologies in non-isolated DC / DC convert...

AI Technical Summary

Problems solved by technology

However, the currently used push-pull circuit topology has disadvantages such as complex circuit, large volume, and low output efficiency.

Images