The effect of supply and substrate noise on jitter in ring oscillators

Measurements, simulations and equations show that differential and single-ended ring oscillators have comparable performance when subjected to the same deterministic noise sources. Both topologies are shown to have a much greater sensitivity to supply noise than substrate noise. It is also shown that symmetrical/asymmetrical noise injection must be considered. The measured results are compared to predictive jitter equations and Spectre/spl reg/ time domain simulations. It is shown that the measurements are in agreement with the simulations and equations.