What is an EMI filter for power supply & how does it work?

What is EMI Filter

What is EMI:

EMI, Electro-Magnetic Interference, is defined as undesirable electrical signals and could be categorized into conducted or radiated emissions. Conducted EMI occurs while the noise travels along the electrical conductors and radiated EMI is generated when the noise travels through the air as radio waves or magnetic fields.

EMI comes from the switching of electrical current and a variety of origins including power supplies. Power supplies convert an input voltage into DC voltages to power on all the electronic components. This process is performed at high frequencies going from kHz to more than a MHz. Electronic devices all rely on power supplies to operate.

How does a EMI filter work:

Almost every electronic device contains an EMI filter. It could be a separate part, an embedded part in circuit boards, or even a built-in component inside the power supply. The main purpose of EMI filter is to reduce high frequency electronic noise which would cause interference with other devices. Most countries have regulatory standards to limit the amount of noise that can emitted.

An EMI filter for a power supply typically consists of passive components, containing capacitors and inductors connected to form LC circuits. The inductors allow DC or low frequency currents to pass through when restraining the undesired high frequency currents. The capacitors offer a low impedance path to divert the high frequency noise from the input of the filter, and go into the power supply, or the ground connection.

Cincon EMI Solution:

While developing a product, engineers may spend lots of time on solving annoying EMI issues in the systems. In this case, EMI filter modules are solutions to the problems.

EMI filter modules are created to reduce the common-mode and differential-mode noise on input or output lines of high-frequency switching power supplies, with the industry standard footprint. With just one module, Cincon saves the trouble for the customers for meeting the EMI requirements of applications. In addition, Cincon offers detailed application notes with circuit layout and other helpful information to support engineers.

Check the product page for more info:

https://www.cincon.com/EMI_Filter.html

If you have further questions, just contact Cincon for more support: sales@cincon.com.tw