CMOS Oscillators for Systems with Autonomous Power

High-speed voltage controlled frequency oscillators in 65nm CMOS are presented. The developed VCOs can be used for internal clock generation purposes in ICs with autonomous power. The design concepts of the existing CMOS VCO schematic realizations with high oscillation frequencies and their features are reviewed. The high speed oscillators based on delay cells with interpolation features are developed and analyzed. The obtained results confirmed the possibility for the presented ring oscillators to operate at 2.5 - 5.5 GHz frequency range.