Resistor-Based Temperature Sensing Chip with Digital Output

Abstract

In this work, a smart temperature sensing chip is proposed for the applications of internet-of-things and wearable devices. A resistor-based temperature sensing bridge is integrated with a fully differential difference amplifier, a 10-bit successive approximation analog-to-digital converter, and timing circuits into a single chip. This chip is designed to sense temperature once per second, and is activated only 64 $\mu$ S per second and stays in the standby mode in the rest of time for reducing power consumption. The proposed chip is designed and fabricated by a 0.18m 1P6M mixed-signal process, and the total area is $953 \times 708$ $\mu m^{2}$. According to the measured results, the linearity between the measured temperature and the digital output is excellent, and it can work with a supply voltage ranging from 1.4 V to 2.0V.