What is Common Mode Choke

Common mode choke generally refers to common mode inductance, which is often used to filter common mode electromagnetic interference signals in computer switching power supply. In the board design, the common mode inductor also plays the role of EMI filtering, which is used to suppress the outward radiation of electromagnetic wave generated by high-speed signal line.

The common mode choke is essentially a bidirectional filter: on the one hand, it is necessary to filter out the common mode electromagnetic interference on the signal line, on the other hand, it is also necessary to restrain itself from sending out electromagnetic interference, so as to avoid affecting the normal operation of other electronic equipment in the same electromagnetic environment.

Nanocrystalline core has become the preferred material for common mode inductor core.

Amorphous and nanocrystalline technology is a modern advanced technology. It directly forms amorphous strip from molten steel through rapid cooling, which is a revolution in the history of metallurgy. As a new type of soft magnetic material, it has been widely used in high-performance magnetic cores, inductive components and transformers because of its unique advantages. Transmart has developed a series of amorphous and nanocrystalline cores for common mode inductors.

Nanocrystalline magnetic core has high permeability and wide frequency characteristics. It is very suitable for EMC filter and common mode inductor to suppress common mode noise. Compared with traditional soft magnetic materials, such as ferrite core, nanocrystalline core has obvious advantages, high inductance, good filtering effect, small volume and less turns of copper wire. Our nanocrystalline magnetic core with 100kHz permeability can reach 20000, which is the leading level in the industry.

The Curie temperature of nanocrystalline core is as high as 560 ℃, which is much higher than that of traditional ferrite core, only 200 ℃. High Curie temperature makes nanocrystalline core have high thermal stability and can work continuously at 120 ℃.