title: Design of an Embedded CMOS Temperature Sensor for Passive RFID Tag Chips.
abstract: This paper presents an ultra-low embedded power temperature sensor for passive RFID tags. The temperature sensor converts the temperature variation to a PTAT current, which is then transformed into a temperature-controlled frequency. A phase locked loop (PLL)-based sensor interface is employed to directly convert this temperature-controlled frequency into a corresponding digital output without an external reference clock. The fabricated sensor occupies an area of 0.021 mm2 using the TSMC 0.18 1P6M mixed-signal CMOS process. Measurement results of the embedded sensor within the tag system shows a 92 nW power dissipation under 1.0 V supply voltage at room temperature, with a sensing resolution of 0.15 °C/LSB and a sensing accuracy of -0.7/0.6 °C from -30 °C to 70 °C after 1-point calibration at 30 °C.
authors.affiliation: School of Electrical and Electronic Engineering, East China Jiaotong University, Nanchang 330013, China. dengfm1980@sina.cn.|School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China. dengfm1980@sina.cn.
authors.forename: Fangming
authors.initials: F
authors.lastname: Deng
authors.affiliation: School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China. 18655136887@163.com.
authors.forename: Yigang
authors.initials: Y
authors.lastname: He
authors.affiliation: School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China. libinghnu@163.com.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.affiliation: School of Electrical and Electronic Engineering, East China Jiaotong University, Nanchang 330013, China. lhzhang@ecjtu.edu.cn.
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhang
authors.affiliation: School of Electrical and Electronic Engineering, East China Jiaotong University, Nanchang 330013, China. zgxiangyu@163.com.
authors.forename: Xiang
authors.initials: X
authors.lastname: Wu
authors.affiliation: School of Electrical and Electronic Engineering, East China Jiaotong University, Nanchang 330013, China. fuzhihui@sohu.com.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Fu
authors.affiliation: School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China. 18655118171@126.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Zuo
keywords: CMOS process; RFID tag; phase-locked loop; temperature sensor