WCSE 2019 SUMMER ISBN: 978-981-14-1684-2
DOI: 10.18178/wcse.2019.06.125

A CMOS Temperature Sensor with an Inaccuracy of 0.5℃ from -20℃ to 80℃

Wenyuan Li, Lei Zhu, Peigen Yu

Abstract— A smart temperature sensor is designed for very large scale integration (VLSI) systems to control power and temperature. PNP transistors are designed as sensing elements to generate temperature dependent output voltage. Three main techniques to enhance the accuracy are described as following: a chopped current gain independent bias circuit, dynamic element matching (DEM) and curvature compensation. To reduce area and power consumption, successive approximation register (SAR) ADC with split capacitor DAC structure is used, which achieves an effective number of bits (ENOB) of 10.4 bits after simulation. The sensor is designed in a TSMC 0.18μm 1P6M standard CMOS technology and consumes 700uA under a supply voltage of 1.8V. The proposed sensor is capable of working in the temperature range of -20°C ~ 80°C. With the one-point calibration, the sensor shows an inaccuracy of 0.5°C.

Index Terms— temperature sensor, dynamic element matching, SAR ADC, offset cancellation

Wenyuan Li, Lei Zhu
Institute of RF-&OE-ICs, Southeast University, CHINA
Lei Zhu, Peigen Yu
School of Information Science and Engineering, Southeast University, CHINA


Cite: Wenyuan Li, Lei Zhu, Peigen Yu, "A CMOS Temperature Sensor with an Inaccuracy of 0.5℃ from -20℃ to 80℃," Proceedings of 2019 the 9th International Workshop on Computer Science and Engineering, pp. 841-846, Hong Kong, 15-17 June, 2019.