Non-linear behaviour of charge-pump phase-locked loops

• Main Authors: C. Wiegand, C. Hedayat, U. Hilleringmann
• Format: Article
• Language: deu
• Published: Copernicus Publications 2010-10-01
• Series: Advances in Radio Science
• Online Access: http://www.adv-radio-sci.net/8/161/2010/ars-8-161-2010.pdf

The analysis of the mixed analogue and digital structure of charge-pump phase-locked loops (CP-PLL) is a challenge in modelling and simulation. In most cases the system is designed and characterized using its continuous linear model or its discrete linear model neglecting its non-linear switching behaviour. I.e., the time-varying model is approximated by a time-invariant representation using its average dynamics. Depending on what kind of phase detector is used, the scopes of validity of these approximations are different. Here, a preeminent characterization and simulation technique based on the systems event-driven feature is presented, merging the logical and analogue inherent characteristics of the system. In particular, the high-grade non-linear locking process and the dead-zone are analyzed.