WCSE 2016
ISBN: 978-981-11-0008-6 DOI: 10.18178/wcse.2016.06.088

A 100kS/s CMOS Time-Domain Temperature Sensor for Wireless Sensor Networks

Yuanxin Bao, Wenyuan Li, Jun Feng

Abstract— This paper presents a smart temperature sensor with digital output, which is suitable to be used in temperature monitoring of wireless sensor networks. A ring oscillator and bias voltage is designed as the temperature sensor to generate quasi-linear temperature dependent output pulses. One-point calibration and low drop-out regulators is adopted to effectively relieve the impact of process and supply voltage variation. A frequency-to-digital converter (FDC) is used to translate frequency into a digital output code. The sensor is designed in a TSMC 0.18μm 1P6M standard CMOS technology and consumes 4nJ of energy at conversion rate of 100kS/s with a resolution of 0.25°C/LSB and a core area of 0.0275mm2. The proposed sensor is capable of working in the temperature range of -45°C ~ 85°C with a supply voltage of 1.4V ~ 2.4V. With the piecewise linear fitting and one-point calibration adopted, the sensor shows an inaccuracy of -1.2°C ~ 1.2°C.

Index Terms— time-domain temperature sensor, wireless sensor networks, low power, wide supply voltage.

Yuanxin Bao, Wenyuan Li, Jun Feng
Institute of RF-&OE-ICs, Southeast University, CHINA


Cite: Yuanxin Bao, Wenyuan Li, Jun Feng, "A 100kS/s CMOS Time-Domain Temperature Sensor for Wireless Sensor Networks," Proceedings of 2016 6th International Workshop on Computer Science and Engineering, pp. 525-528, Tokyo, 17-19 June, 2016.