Simulation and modeling-the macro modeling of phase locked loops for the SPICE simulator

摘要

A modeling approach that uses no semiconductor junctions and no regenerative feedback is described. The voltage-controlled oscillator is implemented by means of a circuit producing essentially infinite ringing, and the comparator characteristics are obtained by means of an odd-order polynomial transfer function. The design of the comparator, phase detector, low-pass filter, and error amplifier are also discussed. Performance of the complete macro-model is such that 8000-point simulations, corresponding to some 150 cycles of local oscillator, can be performed in about 15 min on a platform such as the Sun 3/60, or Apollo DN4500.