An Event-Driven-Based Behavioral Modeling for Fractional-N CP-PLL

The event-driven (ED) model is an efficient, behavioral-level simulation model that is primarily used in mixed-signal simulations. This paper builds a fast and accurate model for fractional-N charge pump phase-locked loop (CPPLL) simulating. In this model, between two adjacent events, the process is divided into two stages. In the first stage, due to the current injection, it is necessary to update the last processing result to improve the accuracy of the model. The second stage is to calculate the result of the next variable set. Compared to the conventional behavioral simulation model, which is simulated by the AMS simulator in Cadence, the proposed model only consumes one-tenth of the time.