Resistor-Based Temperature Sensing Chip with Digital Output

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 μS 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 0.18μm 1P6M mixed-signal process, and the total area is 953×708 μm². 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.