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Discover key EMI mitigation techniques in modern power systems: shielding, filtering, grounding, advanced methods using cutting- edge materials, active cancellation, and noise suppression. Stay updated on future trends and regulatory standards for robust EMI management. Electromagnetic interference (EMI) is a concern in many power systems, particularly those employed in noise-sensitive applications. Examples of these applications include phase- locked loops (PLLs), voltage-controlled oscillators (VCOs), and other radio frequency (RF) applications; high-speed data convertors; precision instrumentation; and post-regulators for switching supplies. Across these applications, EMI can degrade the performance of a circuit, cause a malfunction, or even lead to complete system failure. In some cases, these impacts can have serious consequences. For example, if a medical instrument malfunctions, it could endanger patients' lives. To avoid such issues, regulatory bodies worldwide have established stringent EMI limits and electromagnetic compatibility (EMC) standards. For example, in Title 47, Part 15 of the United States Code of Federal Regulations, the Federal Communications Commission (FCC) regulates intentional, unintentional, or incidental transmissions in electronic devices. In Europe, the Electromagnetic Compatibility Directive (EMCD) 2014/30/EU sets EMC requirements. Globally, CISPR provides standards adopted by many countries, with CISPR 11, 14, and 32 being particularly relevant for industrial, household, and IT equipment, respectively. Similarly, the IEC has developed the IEC 61000 series, which addresses various aspects of EMC. With these requirements in mind, engineers have several techniques available to minimize EMI. These design approaches can help optimize device performance, ensure safe operation, and avoid compliance issues. EMI Mitigation in Modern Power Systems Fundamental Techniques to Future Trends By Brandon Lewis for Mouser Electronics Sources of EMI and Mitigation Measures Power systems must contend with many sources of external EMI, including the following: X Natural sources, such as lightning strikes, solar flares, and cosmic rays X High-powered machinery, such as motors, welding machines, and industrial heaters X Wireless communication devices, including mobile phones, Wi-Fi ® routers, and Bluetooth ® -enabled products X Microprocessors, microcontrollers, and other high-speed digital electronics X Switching power supplies and external RF sources Depending on the source, EMI may be broad-spectrum or occupy a relatively narrow band. It might be introduced into the circuit via electromagnetic waves or injected via cables, PCB traces, or other conductors. Given the diversity of interference a power system might encounter, EMI mitigation typically involves multiple techniques. The primary methods include shielding, filtering, and grounding, each serving a specific purpose in reducing or eliminating interference. Shielding involves enclosing electronic circuits in conductive materials like copper, aluminum, or steel to block external electromagnetic fields and contain internal emissions. Shielding effectiveness depends on the material, thickness, and interfering signal frequency. Filtering involves blocking unwanted high-frequency signals while allowing desired signals to pass. Broadly speaking, filters involve a combination of capacitors, inductors, and resistors used in various combinations to achieve specific effects. For example, a simple low-pass filter consists of a resistor and capacitor in series. 4 ADI | Powering the Future Adobe Stock / Shabnam – stock.adobe.com