Grounding and Shielding of Electronic Systems

Description

Well designed electronic systems operate reliably in their intended electromagnetic environment. They are not affected by voltage spikes on their power or signal lines; they function normally in the presence of strong electric or magnetic fields; and the systems’ own fields do not interfere with other systems nearby. In a well designed system, the cost of grounding, shielding and filtering is usually a negligible percentage of the overall system component costs. Unfortunately, many electronic systems are not well designed. It is not unusual for a company to spend millions of dollars and thousands of man-hours attempting to track down and correct system malfunctions that are the direct result of improper grounding and shielding. This course reviews the fundamental grounding, filtering and shielding concepts that all engineers need to be familiar with in order to ensure the safety and reliability of their products at the lowest possible cost.

Continuing Education Credit: 1.5 CEUs, 15 PDHs

Course Outline

A380 cockpit electronics
  1. Introduction
    • Overview of Electromagnetic Compatibility Failure Mechanisms
    • Examples of Good and Bad System Designs
  2. Current Flow in Systems
    • Tracing Current Paths
    • Concept of Least Impedance
    • Design Examples
  3. Coupling Mechanisms
    • Common-Impedance Coupling
    • Electric Field Coupling
    • Magnetic Field Coupling
    • Radiated Coupling
    • Design Examples
  4. Grounding
    • Ground vs. Signal Return
    • Isolated Grounds
    • Grounding Strategies for Large Systems
    • Grounding Strategies for Black Boxes
    • Grounding for Mixed-Signal Systems
  5. Shielding
    • Shielding Theory
    • Electric Field Shielding
    • Magnetic Field Shielding
    • Shielded Enclosures
    • Cable Shields
  6. Filtering
    • High-Frequency Behavior of Components
    • Power Line Filtering
    • High-Frequency Filtering
    • Transient Protection
  7. Troubleshooting System-Level EMC Problems
    • Identifying the Source
    • Identifying the Coupling Mechanism
    • EMC Troubleshooting Tools and Techniques
    • Effective EM Measurements
    • EM Modeling Tools

Course Instructor

Prof. Todd Hubing

Dr. Todd H. Hubing is a Professor Emeritus of Electrical and Computer Engineering at Clemson University and Director of the Clemson Vehicular Electronics Laboratory. He and his students at Clemson have worked on the development and analysis of a wide variety of electronic products. EMC design rules can vary greatly depending on whether you are designing high-speed computing equipment, low-cost mixed-signal consumer products or high-power industrial controls; but the basic EMC principles are the same in all industries. By applying these principles in an organized manner, it is possible to review a design circuit-by-circuit to guarantee that any particular EMC requirement will be met. This approach is more effective than the blind application of design guidelines and is the primary emphasis of every EMC design class taught by Dr. Hubing.