Intrinsic 1/f device noise reduction and its effect on phase noisein CMOS ring oscillators

摘要

This paper gives experimental proof of an intriguing physicalneffect: periodic on-off switching of MOS transistors in a CMOS ringnoscillator reduces their intrinsic 1/f noise and hence the oscillator'snclose-in phase noise. More specifically, it is shown that the 1/f3n phase noise is dependent on the gate-source voltage of the MOSntransistors in the off state. Measurement results, corrected fornwaveform-dependent upconversion and effective bias, show an 8-dB-lowern1/f3 phase noise than expected. It will be shown that thisncan be attributed to the intrinsic 1/f noise reduction effect due tonperiodic on-off switching