CommonModeChokes
Common mode choke is a passive electrical component that reduces common‑mode noise and electromagnetic interference (EMI) in electronics. It typically consists of two or more windings wound on a shared magnetic core. The core material is usually ferrite or powdered iron, chosen for high magnetic permeability and low core loss at the frequencies of interest. The windings are designed to carry signals with opposite polarity so that differential‑mode currents are largely unaffected, while common‑mode currents induce counter‑rotating magnetic fields that cancel each other and are therefore strongly attenuated.
The choke functions by presenting a high impedance to common‑mode currents. When such a current flows, the
Common mode chokes are widely used in power supplies, USB and Ethernet interfaces, and battery chargers to