A supply-insensitive self-regulating CMOS ring oscillator

This paper presents a resistor-free self-regulating CMOS ring oscillator (RO) whose oscillation frequency is insensitive to supply noise variations. The proposed RO design achieves self-regulation by adopting a cross-coupled dual latch-based scheme; Proper custom device sizing of the cross-coupled latches can improve supply noise immunity and frequency stability compared to a simple inverter design. A Five-stage RO is designed and implemented as a test vehicle which shows > 40% improvement in reducing supply noise sensitivity with a maximum frequency of 1GHz and 0.7mW power consumption. The simulation results are obtained using the Spectre simulator based on digital CMOS 0.09μm process Technology.