The monolithic phase-locked loop-a versatile building block

The basic tem, known since the early used in a variety of applications in instrumentation and space telemetry. However, because of its cost and complexity in discrete (nonintegrated) system design, its application has been limited to precision measurements requiring a high degree of noise immunity and very narrow bandwidths. With the recent developments in integrated circuit design and processing technology, this situation is rapidly changing. The monolithic PLL is now emerging as a new and versatile building block, similar to the monolithic operational amplifier in the diversity of its applications. The availability of a lowcost PLL system in a monolithic circuit package opens up many new applications that cost and complexity previously precluded. The purpose of this article is to acquaint the reader with the basic principles and design parameters of an integrated PLL, as well as with the wide range of applications it offers in both analog and digital signal processing.