Mar 22,2023
How does a common-mode suppression inductor work?
A common-mode suppression inductor is a type of inductor used to suppress high-frequency noise and interference in electronic circuits. It works by providing a high impedance path to the common-mode noise while allowing the differential-mode signal to pass through with minimal attenuation.
To understand how it works, it's important to understand the difference between differential-mode and common-mode signals. Differential-mode signals are signals that appear across a pair of conductors, such as the two wires of a twisted-pair cable, while common-mode signals are signals that appear on both conductors with respect to a reference point, such as ground.
When a common-mode signal is present, the common-mode suppression inductor provides a high impedance path to the noise, which reduces its amplitude and prevents it from being coupled into the rest of the circuit. This is achieved by having a winding on the inductor that is connected to ground, which creates a low-impedance path for the common-mode signal to flow through, while the differential-mode signal passes through the inductor unaffected.
The common-mode suppression inductor can also help to reduce electromagnetic interference (EMI) by acting as a low-pass filter, blocking high-frequency noise and allowing low-frequency signals to pass through.
Overall, the common-mode suppression inductor is an effective tool for reducing common-mode noise and interference in electronic circuits, and is commonly used in applications such as power supplies, motor drives, and audio circuits.
