Electromagnetic compatibility (EMC) has become a major concern for integrated circuits (ICs), which is still not perfectly understood by electronic designers. Electromagnetic emission and immunity issues need to be thoroughly understood by professionals to successfully design their ICs, packages or printed circuit boards (PCB). Modelling constitutes a powerful way of analysing the root cause of EMC problems, predicting EMC performance or validating a design to mitigate an EMC problem before fabrication.
This book is dedicated to undergraduate, graduate and post-graduate students and engineers in electronic design who want to learn more about EMC at IC level. The content of the book covers the basic notions for learning how to model circuits and their surrounding environment (PCB) with respect to emission, immunity and signal integrity issues. This book is accompanied by the freeware IC-EMC to illustrate theoretical concepts as well as practical case studies. The book also provides a series of exercises.
Alexandre Boyer and Etienne Sicard are professors in Electronics at INSA de Toulouse. Their researches deal with EMC of ICs. They are members of Laboratoire d'Analyse et Architecture des Systèmes (LAAS-CNRS) and Institut de Recherche en Informatique de Toulouse (IRIT-CNRS) respectively.
INTRODUCTION TO THE ELECTROMAGNETIC COMPATIBILITY OF INTEGRATED CIRCUITS
Before addressing integrated circuits (ICs), this chapter defines the notions of electromagnetic interference and electromagnetic environment, with a brief overview of the sources of electromagnetic disturbances which can affect the operation of electrical, electronic and radio equipment. Some examples of real cases of failures induced by electromagnetic disturbances are then presented to highlight the risks for the safe operation of electronic Systems and the need for electromagnetic compatibility (EMC). The notions of emission, immunity, susceptibility and coupling path are defined. As EMC is extremely important for safety reasons, it is a legal requirement in most countries. This chapter briefly describes aspects of EMC regulations in Europe and the USA. Although EMC is not a legal requirement for integrated circuits, this introduction explains why EMC has become a serious concern for both IC manufacturer and end users. Finally, the book's scope and organisation are presented.
1. Electromagnetic interference
Electromagnetic interference (EMI) is the disturbance of an electrical or electronic device's operation (e.g. error, loss of performance or degraded operation) caused by electromagnetic fields produced by an external source.
EMI can be induced by natural or man-made sources, as explained in part 2. Incoming disturbing signals or electromagnetic (EM) noise are coupled to the victim equipment through one or more of the following three mechanisms :
■ the disturbing signals are conducted from the source to the victim over a power supply network, for example. This is known as conducted coupling;
■ the disturbing signals are induced on the victim by the nearby presence of the source. This coupling mechanism, related to electric field and/or magnetic field coupling, is known as crosstalk;
■ the source produces EM radiation which is coupled to the victim through what is known as radiated coupling.
When the disturbing signal spectrum lies in the radio frequency (RF) range, i.e. the practical frequency range of radiocommunications from 30 kHz up to 10 GHz, EMI is also called radio frequency interference (RFI).