Articles | Volume 8
Adv. Radio Sci., 8, 161–166, 2010
https://doi.org/10.5194/ars-8-161-2010
Adv. Radio Sci., 8, 161–166, 2010
https://doi.org/10.5194/ars-8-161-2010

  01 Oct 2010

01 Oct 2010

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

C. Wiegand1,2, C. Hedayat1, and U. Hilleringmann1,2 C. Wiegand et al.
  • 1Fraunhofer ENAS, Department Advanced System Engineering (ASE), Warburger Str. 100, 33098 Paderborn, Germany
  • 2University of Paderborn, Department of Sensor Technology Warburger Str. 100, 33098 Paderborn, Germany

Abstract. 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.