common mode choke

A **Common Mode Choke (CMC)** is a passive magnetic component for EMI suppression. It consists of two identical windings, wound oppositely on the same ferrite core.

- For **normal differential working current**: Magnetic fluxes from two coils cancel each other. It shows very low impedance and has nearly no impact on normal power or signal transmission.
- For **common-mode noise**: The noise currents flow in the same direction on both lines. Magnetic fluxes superpose, creating high impedance to block and attenuate common-mode electromagnetic interference