Time-domain simulation of quantization noise mixing and charge pump device noise in fractional-N PLLs

In this paper we model phase noise and spurious tones (spurs) for a fractional-N phase-locked loop (PLL) with static phase offset. The phase detector (PD) input-output characteristic around the bias point is approximated by a parabolic function. Using a MATLAB code, phase noise spectrum and fractional spurs are calculated as a function of slope and curvature of the PD characteristic. The dependence of the PLL output spectrum on PD nonlinearity and rms phase error at the PD input is discussed and compared with theoretical results. A close agreement with theoretical predictions is observed.

[1]  Bram De Muer,et al.  On the analysis of ΔΣ fractional-N frequency synthesizers for high-spectral purity , 2003, IEEE Trans. Circuits Syst. II Express Briefs.

[2]  Juha Kostamovaara,et al.  Techniques for in-band phase noise reduction in /spl Delta//spl Sigma/ synthesizers , 2003 .

[3]  C. Gardiner.  Handbook of Stochastic Methods , 1983 .

[4]  Christoph Scheytt,et al.  Analytical Phase-Noise Modeling and Charge Pump Optimization for Fractional-$N$ PLLs , 2010, IEEE Transactions on Circuits and Systems I: Regular Papers.

[5]  F. Herzel,et al.  System-level simulation of a noisy phase-locked loop , 2005, European Gallium Arsenide and Other Semiconductor Application Symposium, GAAS 2005.

[6]  R. Leighton,et al.  The Feynman Lectures on Physics; Vol. I , 1965 .

[7]  Hung-Ming Chien,et al.  A 4GHz Fractional-N synthesizer for IEEE 802.11a , 2004, 2004 Symposium on VLSI Circuits. Digest of Technical Papers (IEEE Cat. No.04CH37525).