Study of CMOS-SOI Integrated Temperature Sensing Circuits for On-Chip Temperature Monitoring

Maria Malits; Igor Brouk; Yael Nemirovsky

doi:10.3390/s18051629

Study of CMOS-SOI Integrated Temperature Sensing Circuits for On-Chip Temperature Monitoring

Sensors (Basel). 2018 May 19;18(5):1629. doi: 10.3390/s18051629.

Authors

Maria Malits¹, Igor Brouk², Yael Nemirovsky³

Affiliations

¹ Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel. maria.malits@gmail.com.
² Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel. bigor@tx.technion.ac.il.
³ Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel. nemirov@ee.technion.ac.il.

Abstract

This paper investigates the concepts, performance and limitations of temperature sensing circuits realized in complementary metal-oxide-semiconductor (CMOS) silicon on insulator (SOI) technology. It is shown that the MOSFET threshold voltage (V_t) can be used to accurately measure the chip local temperature by using a V_t extractor circuit. Furthermore, the circuit's performance is compared to standard circuits used to generate an accurate output current or voltage proportional to the absolute temperature, i.e., proportional-to-absolute temperature (PTAT), in terms of linearity, sensitivity, power consumption, speed, accuracy and calibration needs. It is shown that the V_t extractor circuit is a better solution to determine the temperature of low power, analog and mixed-signal designs due to its accuracy, low power consumption and no need for calibration. The circuit has been designed using 1 µm partially depleted (PD) CMOS-SOI technology, and demonstrates a measurement inaccuracy of ±1.5 K across 300 K⁻500 K temperature range while consuming only 30 µW during operation.

Keywords: CMOS-SOI; Vt extractor circuit; proportional to absolute temperature (PTAT); temperature sensor.