Leakage inductance energy absorption circuit for Flyback converters

Abstract

A leakage inductance energy absorption circuit for Flyback converters, which is disclosed by the invention, can effectively absorb the energy accumulated in parasitic inducers and clamp switching voltage, consequently, surge current can be inhibited, the effect of eliminating the voltage peak of a main switch can be effectively realized, the efficiency of a system can be greatly increased as well while the temperature rise of the main switch can be decreased, and moreover, a stable output voltage can be obtained by means of the leakage inductance energy absorption circuit. The invention as the leakage inductance energy absorption circuit for Flyback converters can be widely applied in power supply products.

Description

technical field [0001] The invention relates to the field of electronic circuits, in particular to a leakage inductance energy absorbing circuit for a Flyback converter. Background technique [0002] Flyback converters are commonly known as single-ended flyback DC-DC converters, also known as flyback Flyback converters, or Buck-Boost converters. The Flyback converter circuit is derived from the Buck-Boost circuit using the coupling function of magnetic components. Come. During the turn-on period of the main switch tube of the Flyback converter, the circuit only stores and does not transfer energy, and only transfers energy to the load when the main switch tube is turned off. [0003] In a switching power supply, most of the main components are parasitic inductance and capacitance. The parasitic capacitance is generally connected in parallel with the switching element or diode, and the parasitic inductance is usually connected in series with it. Due to the effects of these ...

AI Technical Summary

Problems solved by technology

On the other hand, the voltage surge of the switch off and the voltage surge of the diode reverse recovery may damage the semiconductor components and generate noise at the same time

[0004] There are three kinds of traditional leakage inductance energy absorbing circuits. The first is the RCD lossy leakage inductance absorbing circuit. This circuit transfers the leakage inductance energy to the resistor for consumption, which can eliminate voltage spikes, but the efficiency of the system is low; the second is The second is an active clamping circuit, which can not only eliminate voltage spikes and improve system efficiency, but also achieve soft switching, but the circuit is more complex; the third is a passive clamping circuit, this The circuit can also eliminate voltage spikes and improve system efficiency, but in this way, in the closed-loop design, because the potentials of the two ports of the secondary output are floating relative to the power ground of the primary side, there will be a certain degree of uncertainty in the design. complexity, and can lead to loss of the original isolation performance of the transformer

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