Flyback converter leakage inductor absorption and feedback circuit

Abstract

The invention discloses a flyback converter leakage inductor absorption and feedback circuit, and belongs to the technical field of an integrated circuit. The circuit combines leakage inductor energy absorption and a feedback circuit together, is composed of a clamping capacitor C1 and a clamping switch tube S2, and is simple and reliable in structure and convenient to control. Compared to a conventional RCD absorption mode, the capacitor C1 only functions to absorb leakage inductor energy and release the leakage inductor energy to a main circuit when the switch tube is conducted, realizes absorption and feedback of the leakage inductor energy and effectively improves the efficiency of a flyback converter. At the same time, since the conduction time sequence of the switch tube S2 and the conduction time sequence of a switch tube S1 are the same, the requirements for the time sequence driving design of the S2 are greatly simplified, and such a control mode is also applied to flyback transformation circuits of any modes. The circuit structure provided by the invention has an advantage in a small-power flyback converter.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, in particular to a flyback transformer leakage inductance energy absorption feedback circuit. Background technique [0002] Due to the advantages of simple structure, low cost, small number of components, easy control, and support for multiple output voltages, flyback converters are widely used in low-power power supplies and low-power inverters. In recent years, in order to achieve higher efficiency and smaller size, the operating frequency of converters has been greatly improved. However, as the operating frequency continues to rise, the leakage inductance loss of the flyback transformer becomes an important bottleneck restricting the conversion efficiency of the converter. [0003] The leakage inductance energy absorption and feedback circuit of the flyback transformer is extremely necessary, it absorbs and releases the leakage inductance energy into the main power circuit, elimin...

AI Technical Summary

Problems solved by technology

[0005] The present invention is suitable for flyback circuits in continuous, discontinuous and critical discontinuous operating modes, and solves the problems of the current critical discontinuous operating mode flyback transformer leakage inductance energy absorption and feedback circuit and its control are too complicated, and improves Reliability and Efficiency of Flyback Circuit

Images