Control circuit and method for step-down circuit

A technology of step-down circuit and control circuit, which is applied in the direction of control/regulation system, electrical components, and regulation of electric variables, etc. It can solve the problem of large input current harmonics of the step-down circuit, and achieve the effect of optimizing harmonics

Pending Publication Date: 2018-07-27
JOULWATT TECH INC LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a control circuit and control method for optimizing the harmonics of the step-down circuit, so as to solve the problem of relatively large input current harmonics of the step-down circuit in the prior art

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  • Control circuit and method for step-down circuit
  • Control circuit and method for step-down circuit
  • Control circuit and method for step-down circuit

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Embodiment Construction

[0032] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. The present invention covers any alternatives, modifications, equivalent methods and schemes made within the spirit and scope of the present invention.

[0033] In order to provide the public with a thorough understanding of the present invention, specific details are set forth in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details.

[0034] In the following paragraphs the invention is described more specifically by way of example with reference to the accompanying drawings. It should be noted that all the drawings are in simplified form and use inaccurate scales, which are only used to facilitate and clearly assist the purpose of illustrating the embodiments of t...

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PUM

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Abstract

The invention discloses a control circuit for a step-down circuit. The control circuit includes a reference signal generating circuit and a ramp signal generating circuit. The reference signal generating circuit receives a sampling signal and a current reference signal characterizing the inductor current to generate a first reference signal. The ramp signal generating circuit receives the first current, and obtains a ramp signal by charging and discharging the first capacitor; the first reference signal or/and the first current is proported. Before the ratio adjustment, the ratio of the firstreference signal to the first current is k1; after the ratio adjustment, a second reference signal and a second current are respectively obtained, and, the ratio of the second reference signal to thesecond current is k2; the ratio of k2 to k1 is shown in the description, where D is the main power tube duty cycle of the buck circuit; the reference voltage including the second reference signal is compared with the ramp signal to generate a control signal for controlling the main switch of the buck circuit to be turned on or off. The control circuit is capable of optimizing harmonics in the buckinput current.

Description

technical field [0001] The invention relates to the field of power electronics, in particular to a control circuit and a control method for a step-down circuit. Background technique [0002] THD (total harmonic distortion) refers to the harmonic component of the output signal that is more than the input signal when the signal source is input, because the system is not completely linear, usually expressed as a percentage. Switching converter circuits have been widely used in the field of power conversion due to their high efficiency and easy control. In AC-DC conversion, in order to prevent the input current of the converter from polluting the power grid, the converter is usually required to meet the power factor and harmonic requirements specified by the industry or each country / region. [0003] In the prior art, the schematic diagram of the control circuit used for the step-down circuit is shown as figure 1 As shown, compare the reference voltage VREF with the ramp signal...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02M3/156H02M7/217H02M1/12
CPCH02M1/12H02M3/156H02M7/217H02M1/0006
Inventor 查振旭黄必亮周逊伟
Owner JOULWATT TECH INC LTD
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