Common mode inductors and differential mode inductors are two common types in inductive devices, they are mainly used for filtering and suppressing electromagnetic interference (EMI), but their working principles and applications are different.
  1. Common-Mode Inductor
    Working principle: Common mode inductors are mainly used to suppress common mode noise. Common mode noise is a noise signal in the same direction that occurs simultaneously on two signal lines (such as power or data lines). The characteristic of the common-mode inductor is that it can prevent the common noise signal in the signal line from entering the circuit at the same time.
    Construction: Generally, a common mode inductor is composed of two windings, and the position and direction of the windings are symmetrically configured to work together. It can filter out the common mode noise in two signal lines simultaneously.
    Application: Used to suppress common mode noise on power cables, data cables or other communication lines, commonly found in power modules, communication devices and power filters.
    2. Differential Mode Inductor
    Working principle: Differential mode inductors are mainly used to suppress differential mode noise. Differential mode noise refers to the noise signal that appears in opposite directions on two signal lines (such as power cables or data lines). The function of the differential mode inductor is to filter out the differential mode noise between the two signal lines.
     Structure: The differential mode inductor is usually composed of a single winding, which is mainly used to suppress the noise in the positive and negative directions on the signal line.
    Application: It is mainly used to filter out differential mode noise, which is commonly used in differential mode filtering in power supply and telecommunications equipment.
    Summary and comparison:
    Noise type: Common mode inductors suppress common mode noise, and differential mode inductors suppress differential mode noise.
    Structure: Common mode inductors are usually composed of two symmetrical windings, and differential mode inductors are generally single windings.
    Application: Common mode inductors are usually used to deal with common mode interference in power lines or data lines, and differential mode inductors are mainly used to filter out differential mode noise.