Q.
What is the difference between common mode and differential mode?
- EMC Components >
- Signal Line Common Mode Chokes/Filters
A. The common mode refers to signals or noise that flow in the same direction in a pair of lines.
The differential (normal) mode refers to signals or noise that flow in opposite directions in a pair of lines.
As an example for convenience, consider a configuration where two copper wires are wound around a ring-shaped ferrite core. In this structure, two patterns may exist: one where the currents in the wires flow in the same direction, and another where they flow in opposite directions. These two patterns are “common mode” and “differential mode”.