Simultaneous Estimation of Temperature and Voltage from Digital Delay Diversity

Semiconductor devices are fundamentally sensitive to process variation, supply voltage, and temperature, which impacts both the design and performance of modern integrated circuits. On-chip sensors are typically designed and calibrated to measure temperature and voltage independently, but designing independent sensors has implicit power and area costs. Here we propose a new simultaneous estimation of temperature and supply voltage using an ensemble of digital logic delays and nonlinear regression models. This approach is inherently digital and compatible with modern digital design flows. Using simulations in commercial 12nm FinFET and 65nm bulk CMOS processes, we show the feasibility and efficiency of this approach, and consider its benefits and potential limitations.