The Design Considerations and Challenges in MOS-Based Temperature Sensors: A Review

This review paper categorizes the state-of-the-art MOS (metal oxide semiconductor)-based temperature sensors according to their thermal sensing principles, including: type I, the logic, saturation and linear MOS-based temperature sensors; type II, the subthreshold MOS-based temperature sensors; and type III, the gate leakage-based temperature sensors. It also discusses in detail the design considerations and challenges of MOS-based temperature sensors, in terms of area, energy efficiency, supply voltage, inaccuracy, noise, as well as process and power supply variations. Based on the aforementioned discussions, the paper concludes that the future MOS-based temperature sensors will mostly likely be based on subthreshold MOS operation, with better trade-offs between area, energy efficiency and accuracy, and with reduced power supply sensitivity and level, as well as a lower-cost, fewer-point calibration method.