Knacks for EMI Solution: To know it or not makes big difference

This time, I would like to talk about EMI suppression (EMI: conducted and radiated emissions).

“I designed it properly, but the EMI noise couldn’t comply with regulations. Why?”
Have you ever wondered like this?

Electronic circuits often do not work according to the schematic. And the higher the frequency, the more conspicuous the effect becomes. The same is true for EMI noise problems.

The reason for this is that EMI noise generation and emission are deeply related to parasitic elements not shown in the schematic. In order to suppress EMI noise, it is important to determine the difference between ideal and reality in circuit operation.

#002 EMI Suppression ~ Why does noise emission occur? Suspect a parasitic component ~

Next, since EMI noise is composed of three factors, suppressing any one of them can stop the noise emission.

  1. Noise source
  2. Conduction path
  3. Radiating element

In general, the essential solution is to take measures on the upstream side.

Rather than preventing the noise from being radiated, it is a better idea to prevent the noise from being transmitted to the radiating element, and even better to prevent the noise from being generated than to prevent the noise from being transmitted to the radiating element.

#003 EMI Suppression ~ Three factors of noise emission. Take countermeasures in upstream ~

The first step in EMI suppression is to figure out where the noise in question is coming from, i.e., what the source of the noise is.

The helpful way to locate the noise source is to figure out the frequency of the noise and then use noise analysis tools.

In order to know the state of the noise, you first use “Electromagnetic Field Visualization System” (-> EMI (Conducted and Radiated Emissions) Suppression and Evaluation Service) in an anechoic chamber to capture the noise emission, and then use a spectrum analyzer to determine the frequency.

Next, our “Noise frequency analysis tool” can be used to determine the noise source of that frequency.

#004 EMI Suppression ~ To identify the noise source; Understand the frequency and use analysis tools ~

EMI suppression is more efficient if you follow these basics. We hope you will try it.

There are many other articles on our web pages which will give you hints on EMI suppression.
Among them, “Electronic Circuit Design Tips PLUS” and a YouTube videos are sure to be of particular interest to you.

If you have taken various countermeasures by yourself and still can’t suppress the EMI noise, please contact us first.

The inquiry is free of charge.

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EMI (Conducted and Radiated Emissions) Suppression and Evaluation Service

EMC:  Electro-Magnetic Compatibility
EMI:  Electro-Magnetic Interference

 

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