Resonant converter provided with overcurrent protection device and control method thereof

Abstract

The invention discloses a resonant converter, comprising a first input terminal, a second input terminal and an overcurrent protection device as well as a first resonant capacitor and a second resonant capacitor; wherein the input terminals are used for receiving an input voltage; the overcurrent protection device comprises a first diode provided with a cathode and a second diode provided with an anode and a cathode as well as a first voltage assembly, wherein the anode is coupled with the second input terminal; the first voltage assembly is provided with a negative terminal and a positive terminal, wherein the negative terminal is coupled with the first input terminal and the positive terminal is coupled with the cathode of the first diode; the first resonant capacitor is provided with a first terminal and a second terminal, wherein the first terminal is coupled with the negative terminal of the first voltage assembly, and the second terminal is coupled with the cathode of the second diode; and the second resonant capacitor is provided with a first terminal coupled with the second terminal of the first resonant capacitor.

Description

technical field [0001] The invention relates to an overcurrent protection device and method in a resonant circuit, in particular to an overcurrent protection device and method in a DC / DC resonant converter. Background technique [0002] The development trend of DC / DC converters, like most power supply products, is towards high efficiency, high power density, high reliability and low cost. . Resonant converters such as LLC converters are more and more used in DC / DC converter. [0003] However, in practical applications, over current protection (Over Current Protection: OCP) is a key issue. When overloaded or short-circuited, the resonant current of the resonant circuit is very large. If it is not limited and protected, the converter circuit will be damaged and fail due to excessive current. The OCP circuit can quickly protect the resonant converter circuit when it is overloaded or short-circuited, and can also limit the inrush current during startup. [0004] In order t...

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Problems solved by technology

[0011] The main purpose of this case is to provide a resonant converter with an overcurrent protection device and its control method, which provides overcurrent protection when the secondary side of the resonant converter is short-circuited, and solves the problem of excessive current stress on the primary side of the resonant converter. At the same time, it also solves the problem that the voltage of the resonant capacitor can only be clamped at the input voltage, the current stress of the primary side switch is completely determined by the input voltage, and the design parameters and working range of the resonant converter circuit are limited.

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