TABLE OF CONTENTS The next wave of personal computer enhancements will include circuit interconnections running at microwave frequencies. Differential signaling enables these frequencies, making the subject of differential signaling important. It is critical that you understand what differential signaling, transmitters, receivers, and interconnect circuitry are all about. This chapter examines the meaning of "differential" in the context of transmitters, receivers, and interconnects. In the process, you will also examine common-mode signals and their impact. You will see why differential signaling enables microwave data rates.
It is tempting to ask a question such as, "What is differential signaling?" or "What is a differential driver?" Such questions are issues of philosophy, not of engineering. They are no more the realm of engineering than the question, "What is the meaning of life?" What is within the realm of engineering, are questions such as, "How is a system optimized for the transport of differential signals?" That is an engineering matter, that is the type of thing we are trained for, are good at, love to get our hands into. The distinction is important because "what is?" questions lead to endless discussions that seem to go nowhere, while "how is?" questions lead to engineering insights.
To make the subject of differential signaling as concise as possible, I'll lay out a set of careful definitions. These definitions are intended as a reset. That is, what you may have read in the hobbyist journals about differential signaling is to be forgotten and ignored for the moment. Here,...
