Modeling and Characterization of the 3rd Order Charge-Pump PLL: a Fully Event-driven Approach

In this paper, the event-driven concept is applied to the third order Charge-Pump Phase-Locked Loop (CP-PLL) and leads to the description of a behavioral model based on a set of exact and non-linear recursive equations. A simulator (SIMPLL), written in C and using this model, checks the conventional z-domain approximate stability theory and brings to the fore the strongly non-linear nature of the CP-PLL that a careful and safe design must take into account. Thus, in order to have a more exhaustive design characterization, a statistical analysis method is explored.