This project explores temperature sensor architectures for 3DIC System-on-Chips. Conventional temperature sensors employ carefully tuned voltage references to eliminate Vdd sensitivity, incurring significant area/power consumption overhead. In this project, we employ multiple diverse, imperfect sensors, and rely on sensor fusion to extract temperature. We seek to eliminate supply voltage dependency at the sensor level through statistical-learning based characterization of sensors. The result is an ultra-modular, low-footprint, mostly-digital temperature sensor that can connect directly (without a regulated supply voltage) to a wide range of digital supply voltages. Low HW footprint architecture allows it to be placed ubiquitously across the chip stack to provide fine-grained temporal and local temperature information, bringing opportunities for future thermal and power management applications.