Digital and analog integrated circuits are the fundamental building blocks of today s electronic systems, digital ICs being dominant. They can emulate many functions for which analog circuitry was previously required. Nevertheless, because the real world is largely analog in nature, the analog IC remains the primary interface.

The extraordinary rate of progress in making dynamic random-access memories (DRAM) smaller and more powerful is reflected in their wide use, and, for example, in the rapid obsolescence of lesser-performing computer models.

The microprocessor, over its 30-some-year life span, has become a powerful tool for the design engineer, who embeds it in a broad range of intelligent digital devices.

Finally, Chap. 6.5 in this section covers nanotechnologies. The rapid developments in nanofabrication techniques have spawned a new era in microcomponent developments, including microelectromechanical components (see Chap. 8.5). C.A.

INTRODUCTION

This and the following two sections will discuss the design and application of two major classes of integrated circuits (ICs): digital and analog and their application to both memory and logic circuits, which are shown for both bipolar and complementary MOS (CMOS) technologies.

Digital circuits are the most widespread and commonly used integrated circuits today. They process signals in binary bits. They are distinguished by their function and their performance. Analog circuits are less common and process signals as waveforms.

Analog circuits play a critical role intrinsic to the...