ABSTRACT
The phenomenal growth of integrated circuit technology has been accompanied by increased consumption of discrete circuit components such as resistors and capacitors. Ceramic capacitors account for a major segment of this volume, usage of which is currently more than 300 billion pieces annually. This vigorous component technology is traceable to the Leyden jar of 1745, the first capacitor design to have enjoyed widespread use. In its most advanced, dry design, with metal foil electrodes in contact with glass dielectric, this early device had volumetric efficiency and loss characteristics that are poor by contemporary standards. Nevertheless, it figured in pioneering experiments on the nature of static electricity, including Franklin's lightning investigations, and some others of questionable value.*
The capacitor's basic function, energy storage, has been broadened since the early experiments, to include the blocking of direct current or the coupling
of ac circuits. In bypass applications, the capacitor separates the ac and dc portions of a mixed signal. Alternating currents are also separated by capacitors according to frequency, and the charge-discharge characteristics of resistance-capacitance combinations are applied in timing circuits. Physically large-scale tasks, such as high-energy storage and power factor correction, fall to larger and different types of capacitors than those discussed in this chapter.
