Simulation of digital frequency synthesizer with a filter of the second order
The problems of research of frequency, dynamic and spectral characteristics of pulse-frequency phase-locked systems are considered. As an example, a pulsed system with a phase-frequency detector and the low pass filter of second order is shown. Criteria for a finding of the sustainability of such systems, as well as the sustainability of the stock in amplitude and phase are determined. The optimal stability margin of the filter parameters, putting in a component of the frequency synthesizer is found. Simulation modeling of frequency synthesizer in Matlab Simulink mathematical package is performed. The results obtained demonstrate the change in the voltage level at the output of the filter at the time of switching the division factor, and also at the edges of the spectrum band switching signal.