Signal Integrity and Radiated Emission of High-Speed Digital Systems

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Introduction to Signal Integrity and Radiated Emission in a Digital System

This is an introductory chapter in which the motivations for studying the subjects of Signal Integrity (SI) and Radiated Emission (RE) are discussed.

Signal integrity is a very important task and deals with the need to ensure that electrical signals are of sufficient quality for proper operation. Signal integrity affects all levels of electronics packaging, including, but not limited to, the Integrated Circuit (IC). For high-speed digital products, at the level of an IC package or Printed Circuit Board (PCB), the main issues of concern for SI are reflections occurring because of interconnect discontinuities, noise induced by neighbouring connections (crosstalk), and noise on power distribution, produced by switching of the digital devices. All these noises can cause functional problems if they are not mitigated by controlling parameters such as the characteristic impedance and spacing of interconnects, which, owing to fast switching of the actual digital devices, should be considered as transmission lines. An overview of the noises affecting SI is given in this chapter, leaving a detailed discussion to the following chapters where the different noises are introduced and investigated separately.

The interest in radiated emission is due to the fact that an apparatus or system must be electromagnetically compatible with its environment. Electronic devices generate electromagnetic fields that unintentionally ...