Phase-locked loop techniques. A survey

Phase-locked loop (PLL) is a technique which has contributed significantly toward the technology advancement in communication and motor servo control systems in the past 30 years. Inventions in PLL schemes combined with novel integrated circuit (IC) technology have made PLL devices important system components. The development of better modular PLL ICs is continuing. As a result, it is expected that they will contribute to the improvement in performance and reliability of future communication systems. They will also contribute to the development of higher accuracy and higher reliability servo control systems, such as those involved in machine tools. This paper provides a concise review of the basic PLL principles applicable to communication and servo control systems, gives the configurations of PLL applications and reports a number of popular PLL chips.