Boost converter

Abstract

The invention belongs to the field of switching power sources, and provides a Boost converter. The Boost converter is characterized in that an auxiliary resonance network is additionally arranged on the basis of an existing topological structure, and meanwhile a high-frequency signal and low-frequency signal combined control mode is adopted in a main switching pipe. Internal resonances of the auxiliary resonance network are adopted, at the moment when high-frequency signals are cut off, the voltage across the high-level end and the low-level end of the main switching pipe is increased from zero, and the zero-voltage shutoff of the main switching pipe is accordingly achieved; meanwhile, the voltage across the high-level end and the low-level end of the main switching pipe is decreased to zero at the startup moment or the shutoff period of the high-frequency signals, zero-voltage startup of the main switching pipe is accordingly achieved, and the main switching pipe can work in the high-frequency complete soft switching state or the high-frequency critically-complete soft switching state. In this way, magnetic elements and EMC filters can be small in design size by improving the switching frequency of the main switching pipe, and the size and the weight of the Boost converter are accordingly reduced.

Description

technical field [0001] The invention belongs to the field of switching power supplies, in particular to a Boost converter. Background technique [0002] A switching power supply is a device that adjusts the output voltage by controlling the switching duty cycle of a switching device, and is widely used in various electronic devices such as smart terminals. Boost converter is a common topology of switching power supply. [0003] Such as figure 1 A typical circuit of a Boost converter provided in the prior art is shown, wherein the feedback control and pulse width modulation circuit is used to output a pulse width modulation signal with a certain duty ratio to drive the switch tube Q1 to be turned on or off. The Boost converter can work in three states: the inductor L1 current continuous state, the inductor L1 current critical continuous state, and the inductor L1 current discontinuous state, in which the switch tube Q1 works as a hard switch with high voltage on and high cu...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the embodiment of the present invention is to provide a Boost converter, aiming to solve the problem that the switching frequency of the switching tube is limited due to the switch-on loss and the turn-off loss of the Boost converter provided by the prior art due to the switching tube working in a hard switching state. , which makes the volume and weight of the Boost converter larger

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