How to select the appropriate common mode inductor | GETWELL

For common-mode inductors, there are many kinds of EMI filters, such as ferrite beads, magnetic rings, three-terminal capacitors, differential mode inductors, common-mode inductors and so on. Each element plays an important role in different circuits.It also has a good inhibition effect on common mode inductance, especially for EMI filter and various switching power supply products, so it is particularly important to choose the appropriate common mode inductance.Next, getwell common mode inductor suppliers to tell you how to choose the right common mode inductor.

Principle of common mode inductance

Common mode inductance is composed of a group of coils with the same number but winding in opposite directions. When the magnetic flux in the magnetic ring is superimposed on each other during the flow, it produces a considerable amount of inductance, which has a inhibiting effect on the common mode current. When the magnetic flux in the magnetic ring is flowing through, it cancels each other out, and there is almost no inductance, so it can pass through without attenuation.Common mode inductance is such a basic principle.

How to choose the appropriate common mode inductor, we need to consider which specifications of the SMT common mode inductor.

1. Packaging volume

Common mode inductors have plugins and patches, and overall molding, according to the actual circuit selection, plugins can not only install patches.

2. Leakage inductance size

Because of the specifications of the common-mode inductor, such problems as processing technology, caused by common-mode inductor winding cannot be exactly the same, resulting in leakage, the so-called "the leakage inductance of the", pay attention to consider the effect of the differential-mode impedance of signal, especially high speed signal, but the leakage inductance of the produce different is bad, sometimes caused by common-mode inductance of the leakage inductance of the sometimes can save increases the cost of differential mode inductance components.

3. Impedance characteristics

The main consideration of the impedance in the selection of the general should pay special attention to the filtering frequency band, to see the common mode inductance specifications, mainly to see the impedance frequency curve, generally the greater the common mode impedance, the better.For example, the diagram below is a common mode electrical impedance characteristic curve, with different impedance values at different frequencies.

4.other

For example, cost, brand and so on will also become an important factor in choosing common mode inductance.

We believe that after reading, the choice of common - mode inductance has a certain understanding.We are a professional inductor manufacturer from China - getwell electronics, welcome to consult!