VCOs with very low sensitivity to noise on the power supply

Abstract

In this paper a new technique to design VCOs with very low sensitivity to power supply noise, i.e. very high PSRR, is introduced. For these VCOs static supply noise sensitivity of less than 0.05%/V is achievable which is better than previously reported. The idea in this design is to make the voltage to current converter independent of the power supply. A four stage ring oscillator in 0.35/spl mu/m CMOS technology was fabricated and characterized.