Influence of Charge Pump Pumping Nonlinearities and a Fractional Frequency Divider with a Delta-Sigma Modulator on the Noise Interference Spectrum in the PLL System

摘要

A mathematical model of a PLL with fractional frequency dividers using delta-sigma modulation and a frequency-phase detector with nonidentical values of charge-pump currents is obtained. On the basis of the obtained model, a program has been developed for calculating the level of interference of fragmentation.