What are the application areas of common-mode chokes?

Common-mode chokes have a wide range of applications, primarily including the following areas:

Power Supply Circuits: The most typical application of common-mode chokes is in power supply circuits, where they primarily suppress common-mode interference in power lines. When common-mode noise arises from external environments or internal circuits, the choke's high-impedance characteristics effectively block the conduction of this noise, ensuring the purity of the power line. For instance, at the input stage of switching power supplies, common-mode chokes are often paired with Y-capacitors to filter out high-frequency common-mode noise.

Data Line Protection: Common-mode chokes are also critical for protecting data transmission lines. For instance, in the power circuits of high-speed interfaces like USB and HDMI, these chokes block common-mode noise from entering devices via power cables while preventing crosstalk between signal lines.

New Energy Sector: In photovoltaic inverters and electric vehicle charging stations, common-mode chokes are combined with EMI filters to meet international standards for conducted disturbance limits. This ensures stable device operation while reducing harmonic pollution to the power grid.

Medical Electronics: Medical devices demand stringent electromagnetic compatibility. Common-mode chokes form multi-stage filter networks within these devices, suppressing external interference while preventing leakage of internally generated noise, thereby complying with medical standards.

Communication Circuits: In communication circuits like CAN bus and RS485 bus, common-mode chokes suppress common-mode interference, ensuring stable and reliable communication.