Power supply dependency reduction of Ring Oscillators using self biasing

A novel power supply independent architecture is proposed for Ring Oscillators. The new architecture exploits the advantages of Self/Bootstrapped biasing. Moreover, the proposed method is general and can be applied to any ring oscillator topology; however it has been applied to the weakest one, i.e. Simple CMOS Inverter, to show its robustness. Simulations show that compared to the last competitive topologies, the frequency deviation of the proposed architecture is improved, i.e. 1.5%, whereas for the previous best case it is about 2%. Simulations were performed using ADS simulator, TSMC 0.18 μm-1.8 V model.