Design and simulation of CMOS-based ring oscillator using cadence virtuoso platform for low-power applications

The increasing demand for energy-efficient electronic systems has necessitated the development of low-power and high-performance timing circuits, particularly ring oscillators, which are widely used in voltage-controlled oscillators, temperature sensors, and random number generators. This study aims to design and simulate a five-stage CMOS-based ring oscillator optimized for low-power applications using the Cadence Virtuoso platform, employing the 65 nm CMOS process technology. The objective was to analyze the oscillator's performance under varying supply voltages and temperatures, focusing on oscillation frequency, power consumption, and jitter. Using the Cadence Virtuoso Design Suite, the oscillator was first modeled at the schematic level, followed by layout design and post-layout parasitic extraction using Assura tools. Simulations were conducted at two supply voltages (0.9 V and 1.2 V) and three temperatures (25°C, 50°C, and 75°C). The results demonstrated a clear trade-off between power consumption and performance: the oscillator achieved a maximum frequency of 148.7 MHz at 1.2 V and 25°C and a minimum power consumption of 12.4 µW at 0.9 V and 25°C, with jitter values ranging from 1.6 ps to 2.8 ps. A two-way ANOVA confirmed that supply voltage had a statistically significant effect on both frequency and power consumption (p < 0.001), while temperature had a secondary but notable impact (p < 0.05), with no significant interaction effect. The study concludes that careful transistor sizing, voltage optimization, and simulation-driven layout design using Cadence Virtuoso can result in a highly efficient and stable ring oscillator suitable for integration in modern VLSI systems. The findings offer valuable insights for designing low-power clock generation and sensor systems, with practical recommendations for future circuit implementations in energy-constrained applications.