A simple second-order digital phase-locked loop.A simple second-order digital phase-locked loop has been designed for the Viking Orbiter 1975 command system. Excluding analog-to-digital conversion, implementation of the loop requires only an adder/subtractor, two registers, and a correctable counter with control logic. The loop considers only the polarity of phase error and corrects system clocks according to a filtered sequence of this polarity. The loop is insensitive to input gain variation, and therefore offers the advantage of stable performance over long life. Predictable performance is guaranteed by extreme reliability of acquisition, yet in the steady state the loop produces only a slight degradation with respect to analog loop performance.
Document ID
19730038570
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Tegnelia, C. R. (California Institute of Technology, Jet Propulsion Laboratory, Telecommunications Div., Pasadena Calif., United States)