Dynamic Analysis of RF CMOS Inverter-Based Ring Oscillators using an All-Region MOSFET Charge-Based Model in 28nm FD-SOI CMOS

Due to their continuous nature across all the inversion regions of MOS transistors, charge-based models are a promising analytical tool for preliminary design sizing that brings the advantages of simplicity and accuracy. These models allows for the efficient exploration of a design space while reducing the computational burden associated to complete compact models. In this paper, a method to analyze the dynamic and frequency performances of a single-ended inverter-based ring oscillators is presented. The proposed analysis is based on the time-domain evaluation of the loading currents, as well as of the input and output voltages of the ring oscillator’s constituent inverters, using the Euler method. The novelty of this approach is the use of a 5-parameter charge-based model that considers short-channel effects. The proposed analysis is tested on a practical implementation in 28nm FD-SOI CMOS technology and the results, including the maximum achievable frequency and dynamic efficiency are compared to those obtained using the UTSOI2 model.