Voltage converter and common-mode noise impedance adjusting method

Abstract

The invention provides a voltage converter and a common-mode noise impedance adjusting method and relates to the field of circuits. The common-mode impedance value of a noise source and the impedance value of an EMI filter are made to reach a mismatch state, therefore, the limit to the design of the EMI filter is reduced, and the EMI filter is made to be smaller in size and higher in use efficiency. The method includes the steps that the impedance value of the common-mode noise source is adjusted through adjustment of a balance impedance value in a balancing winding on the voltage converter so as to enable the impedance value of the common-mode noise source and the impedance value of the EMI filter to reach the mismatch state. The voltage converter and the common-mode noise impedance adjusting method are used for enabling the impedance value of the common-mode noise source and the impedance value of the EMI filter to reach the mismatch state.

Description

technical field [0001] The invention relates to the field of circuits, in particular to a voltage converter and a common-mode noise impedance adjustment method. Background technique [0002] As the frequency of switching power supplies continues to increase, the problem of EMI (Electromagnetic Interference) is becoming more and more serious. The traditional method is to add an EMI filter to the system to suppress noise. In order to make the filter suppress noise to the greatest extent, the designer must select the most suitable EMI filter according to the principle of impedance mismatch. Noise source impedance, load terminal impedance and input and output impedance of EMI filter are the key factors to adjust the performance of EMI filter according to the principle of impedance mismatch. [0003] In order to solve the above electromagnetic interference problems, the general practice in the industry is to select the corresponding type of EMI filter according to the high or l...

AI Technical Summary

Problems solved by technology

[0005] The existing technology designs the EMI filter according to the principle of impedance mismatch, adjusts the impedance of the filter so that the noise source impedance and the EMI filter input impedance, the EMI filter output impedance and the load impedance reach the maximum mismatch, but the impedance of the noise source It cannot be described accurately at present, and in the comparison test of the EMI filter for the system, the cost and time wasted make such a design unreasonable and inefficient, if in order to save time and cost Choose to design the EMI filter, that is, leave a large margin when it comes to the EMI filter, so that the volume of the EMI filter becomes very large

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