EMC stands for Electromagnetic Compatibility. It refers to the ability of electronic devices, systems, or system components to coexist harmlessly and operate properly in a shared electromagnetic environment.

In modern society, we are surrounded by various electronic devices and systems, such as computers, mobile phones, televisions, and wireless communication systems. These devices generate electromagnetic radiation during operation and are also sensitive to the surrounding electromagnetic environment. When multiple devices share an environment, electromagnetic interactions between them may cause interference that affects their performance, reliability, and safety.

The goal of EMC in switching power supplies is to ensure interoperability and compatibility between the power supply and the system in an electromagnetic environment while minimizing interference and faults. It involves the following two aspects:

1. EMI (Electromagnetic Interference): Electromagnetic radiation emitted by electronic equipment during operation that may interfere with other equipment and systems. EMI control involves circuit design, layout, shielding, and other techniques to reduce radiated and conducted interference.

2. EMS (Electromagnetic Susceptibility): The degree to which a device or system is sensitive to external electromagnetic fields and susceptible to interference that causes errors or performance degradation. EMS control includes interference-resistant design, electromagnetic shielding, filtering, grounding, and other techniques to improve immunity.

EMC implementation requires compliance with relevant international standards and specifications, such as the IEC 61000 series, to ensure equipment compatibility and compliance in an electromagnetic environment. Considering and controlling EMC can reduce electromagnetic interference, improve equipment reliability and interoperability, and ensure normal system operation.