Common mode inductance working principle | GETWELL

How does a common mode inductor work?Gev Electric is here to explain.

Common-mode inductors, also known as common-mode chokes, are commonly used to filter common-mode electromagnetic interference signals in switching power supplies of computers.In board card design, common-mode inductor also plays the role of EMI filter, which is used to suppress the electromagnetic wave emitted by high-speed signal line.

Common mode inductance working principle

The filter circuit of common mode inductor, LA and LB are common mode inductor coils.The two coils are wound around the same core, with the same number of turns and the same phase (wound in reverse).Thus, when the normal current in the circuit flows through the common-mode inductor, the current cancels out by generating opposing magnetic fields in the inductor coil wound in the same phase, and the normal signal current is mainly affected by the coil resistance (and a small amount of damping due to leakage inductance).

When there is a common-mode current flowing through the coil, because of the common-mode current in the same direction, it will produce a magnetic field in the coil and increase the coil's inductive reactance.The coil is characterized by high impedance and strong damping effect, so as to attenuate common mode current and achieve the purpose of filtering.

A small common - mode inductor produced in China adopts high - frequency noise suppression.Common mode choke coil structure, no signal attenuation, small size, easy to use, with good balance, easy to use, high quality and other advantages.Widely used in double balance tuning devices, multi-frequency transformers, impedance transformers, balanced and unbalanced conversion transformers...And so on.

There is also a common mode filter inductor /EMI filter inductor using ferrite core, double wire winding, noise suppression strategy is good.High common mode noise suppression and low differential mode noise signal suppression, low differential mode noise signal suppression interference source.It is difficult to deform in high speed signal. It has the advantages of small size, good balance, easy to use and high quality.Widely used in the suppression of electronic equipment EMI noise, personal computers and peripheral devices USB lines, DVC, STB IEEE1394 lines, LCD panel, low voltage differential signal.

So that's how common mode inductors work.We are a professional inductor manufacturer, Huizhou Gewei Electronic Co., Ltd. Hope this article will let you know more about common mode inductor.