EMC

EMC, or electromagnetic compatibility, is the ability of electrical equipment to function properly in its electromagnetic environment and not to generate or respond to interference that could disrupt other devices. It encompasses two related ideas: emissions, the unwanted generation or radiation of electromagnetic energy by a device, and immunity, the device’s ability to tolerate external electromagnetic disturbances without functional degradation.

Standards and testing define what is acceptable in terms of emissions and immunity. International and national frameworks include the IEC 61000 series and CISPR standards, such as CISPR 11, 22, and 32, along with regulatory requirements like the FCC Part 15 in the United States and VCCI in Japan. Testing covers conducted and radiated emissions, radiated and conducted immunity, as well as specialized tests for electrostatic discharge (ESD), electrical fast transient/burst, surge, and harmonic/current distortion. Measurements are taken with calibrated equipment in controlled environments, often using LISNs, calibrated antennas, and shielded test chambers.

Design and compliance practices focus on minimizing emissions and maximizing immunity. Techniques include shielding and enclosure design, filtering on power and signal lines, robust grounding and bonding, careful printed circuit board layout to minimize loop areas, proper decoupling and bypassing, use of ferrites, and thoughtful cable management to reduce coupling and resonance. Early and iterative pre-compliance testing helps identify issues before formal certification.

EMC is essential across many sectors, including consumer electronics, automotive, medical devices, and industrial equipment. Achieving EMC enables market access, protects reliable operation, and reduces the risk of interference with other systems.