A wideband low-spur 0.18-mu m CMOS phase-locked loop with bandwidth calibration

摘要

This paper presents a 0.18-mu m complementary metal-oxide-semiconductor wideband phase-locked loop with low reference spurs. The dual-level charge-pump current calibration technique is proposed to maintain a constant loop bandwidth for wide operation frequency range and achieve low reference spurs. The first level charge-pump current calibration is seamlessly incorporated in the automatic frequency band hopping control and the mechanism also ensures enough negative transconductance for the voltage-controlled oscillator to function throughout the whole frequency range. The charge-pump current mismatch is calibrated by the second level charge-pump current calibration combined with the pulse-width scaling technique. The operation frequency range of the phase-locked loop covers from 4.7GHz to 6.1GHz. The measured phase noise is-116dBc/Hz at 1-MHz offset and the reference spurs are below-66.8dBc. Copyright (c) 2015 John Wiley & Sons, Ltd.