A CMOS Thermistor-Embedded Continuous-Time Delta-Sigma Temperature Sensor With a Resolution FoM of 0.65 pJ degrees C-2

作者：Weng Chan Hsiang^*; Wu Chun Kuan; Lin Tsung Hsien

来源：IEEE Journal of Solid-State Circuits, 2015, 50(11): 2491-2500.

DOI：10.1109/JSSC.2015.2470517

• Delta-sigma modulator
• operational amplifiers
• smart sensor
• thermistor-embedded
• trimming technique
• Wien-bridge

In a smart temperature sensor system, two individual building blocks, a sensing front-end and an analog-to-digital converter, are cascaded to implement the temperature-to-digital conversion. In this work, a thermistor-embedded continuous-time delta-sigma modulator (CTDSM), which merges these two building blocks into one, is proposed for a hardware- and energy-efficient temperature acquisition. The thermistor-based sensing front-end is reused in a 2nd-order 1 bit CTDSM to attain a high-resolution, low hardware complexity, and energy-efficient temperature sensing. Furthermore, a resistor-ladder with a switch on-resistance compensation scheme is proposed to implement the trimming circuit. Over a range of -45 degrees C similar to 125 degrees C, the proposed smart temperature sensor consumes 64.5 mu W from 1.5 V supply voltage and achieves a resolution around 0.01 degrees C rms (1 sigma) temperature resolution with a single conversion time of 100 mu s. The corresponding resolution FoM is 0.65 pJ degrees C-2. With 1-point trimming, this design achieves +/- 1 degrees C temperature inaccuracy; this inaccuracy can be further improved to +/- 0.4 degrees C with additional batch calibration.

• 出版日期2015-11
• 单位中国科学院电工研究所