Bootstrap boosting SEPIC converter based on synchronous rectification technology

Abstract

The invention discloses a bootstrap boosting SEPIC converter based on a synchronous rectification technology. The converter comprises a synchronous rectification circuit and a bootstrap boosting driving circuit. The synchronous rectification circuit increases current allowed to pass the circuit, and the bootstrap boosting driving circuit realizes synchronous rectification. According to the invention, a power type N-channel MOSFET with small on-resistance is used as a rectification switch triode; a grounding switch triode and the rectification switch triode are in opposite order of conduction and have complementary on-time; by controlling the working order of the grounding switch triode and the rectification switch triode, the synchronous rectification function of the synchronous rectification SEPIC converter is realized; in addition to switching loss in the circuit, the loss on the rectification switch triode is only the loss caused by extremely low on-resistance; in the case of high duty ratio, the circuit loss is greatly reduced, and the overall efficiency of the SEPIC converter is improved; and the output current level of the SEPIC converter is improved while taking into accountthe heat dissipation package and heat dissipation conditions of a rectification component.

Description

technical field [0001] The invention relates to a device and method for a bootstrap boost SEPIC converter based on synchronous rectification technology, which belongs to the field of power supplies, and in particular relates to a SEPIC converter. Background technique [0002] With the development of life and industry, the requirements for power converters are getting higher and higher. Power converters with both step-up and step-down functions are used in battery charging and discharging, super capacitor charging and discharging, automotive applications, and need to provide multiple inputs. There are more and more applications in fields such as photovoltaic power generation systems with a large output voltage range, so the research on power converters has become particularly important. [0003] The single-ended primary winding inductive converter (SEPIC) is a step-up-buck converter that allows the output voltage to be greater than, less than or equal to the input voltage of ...

AI Technical Summary

Problems solved by technology

[0004] The existing SEPIC converter realizes the rectification switching function through the diode, and the forward conduction voltage drop of the diode will increase with the increase of the conduction current, which will eventually lead to a large current flowing through the diode. , the power dissipation on the rectifier diode accounts for a high proportion of the power dissipation of the entire SEPIC converter, which not only reduces the overall efficiency of the entire SEPIC converter, but also has to be reduced in order to take into account the diode heat dissipation package and heat dissipation conditions in practical applications Converter output current rating

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