White Paper: Design
Fundamentals of Electromagnetic Compliance
SPONSORED BY: ![]()
The continual increased use of electronics and electrical products has led to an environment filled with many signal and noise sources across a wide range of frequencies. This paper explains how fields interact to create intentional and unintended transmitters and receivers, and how applying EMI mitigation techniques when designing and testing can lead to positive outcomes in electromagnetic compliance testing.
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Overview
The document on the Fundamentals of Electromagnetic Compliance (EMC) provides a comprehensive overview of electromagnetic interference (EMI) and the importance of designing electronic devices to minimize such interference. As electronic devices become smaller and more powerful, the proximity of components can lead to increased EMI, which can disrupt the functionality of various devices operating in close proximity.
EMI is defined as any undesired electrical disturbance that interferes with the operation of circuits. The document explains that electromagnetic compatibility (EMC) is the ability of electronic equipment to function properly without causing or suffering from interference. This compatibility is verified through testing against industry standards, which specify limits on noise emissions that can vary based on location and application.
The document categorizes noise sources into transient (discontinuous) and continuous emissions, with examples including automatic switches and electric motors. It emphasizes the need to understand the modes of electrical noise propagation—radiated and conducted—to effectively address EMI issues. A fundamental grasp of antenna theory is highlighted as essential for understanding how electric and magnetic fields interact with electronic components.
To aid in achieving EMC, the document provides design hints for passing pre-compliance and compliance tests. Key recommendations include minimizing circuit trace lengths to reduce unintended emissions, considering EMC from the early design stages, and using simulation tools to design and verify noise filters. It also suggests using magnetically shielded inductors and maintaining appropriate spacing between components to mitigate EMI.
The document outlines various EMC standards, including FCC Title 47 Part 15 for radio frequency devices and the IEC 61000 series, which provides guidelines for testing and measurement methods. It also mentions product-specific standards for categories such as electric vehicle charging systems and medical equipment.
In conclusion, the document stresses the growing complexity of the electromagnetic environment due to the proliferation of electronic devices. It advocates for a proactive approach to design and testing to ensure compliance with EMC standards, thereby enhancing the reliability and performance of electronic products in an increasingly noisy electromagnetic landscape. Understanding and applying EMI mitigation techniques is crucial for successful EMC testing and compliance.