Journal of the Institute of Electronics Engineers of Korea SD (대한전자공학회논문지SD)

The Institute of Electronics and Information Engineers (대한전자공학회)
권호 표지

A UHF-band Passive Temperature Sensor Tag Chip Fabricated in $0.18-{\mu}m$ CMOS Process

$0.18-{\mu}m$ CMOS 공정으로 제작된 UHF 대역 수동형 온도 센서 태그 칩

  • Pham, Duy-Dong (School of Electronics and Information, Kyung Hee University) ;
  • Hwang, Sang-Kyun (School of Electronics and Information, Kyung Hee University) ;
  • Chung, Jin-Yong (Electronic and Electrical Engineering, POSTEC) ;
  • Lee, Jong-Wook (School of Electronics and Information, Kyung Hee University)
  • Published : 2008.10.25
Download PDF
⟨ Previous Next ⟩

Abstract

We investigated the design of an RF-powered, wireless temperature sensor tag chip using $0.18-{\mu}m$ CMOS technology. The transponder generates its own power supply from small incident RF signal using Schottky diodes in voltage multiplier. Ambient temperature is measured using a new low-power temperature-to-voltage converter, and an 8-bit single-slope ADC converts the measured voltage to digital data. ASK demodulator and digital control are combined to identify unique transponder (ID) sent by base station for multi-transponder applications. The measurement of the temperature sensor tag chip showed a resolution of $0.64^{\circ}C/LSB$ in the range from $20^{\circ}C$ to $100^{\circ}C$, which is suitable for environmental temperature monitoring. The chip size is $1.1{\times}0.34mm^2$, and operates at clock frequency of 100 kHz while consuming $64{\mu}W$ power. The temperature sensor required a -11 dBm RF input power, supported a conversion rate of 12.5 k-samples/sec, and a maximum error of $0.5^{\circ}C$.

본 논문에서는 무선으로 전력과 데이터를 받는 온서 센서 태그 칩을 $0.18-{\mu}m$ CMOS공정으로 제작하였다. 태그 칩 구동에 필요한 전력은 쇼트키 다이오드로 구성된 전압체배기를 이용하여 리더로부터 받는 UHF 대역 (900 MHz) RF 신호를 이용하여 발생시킨다. 태그 칩이 위치한 부분의 온도는 sub-threshold 모드에서 동작하는 새로운 저전력 온도-전압 변환기를 이용하여 측정되고, 이 아날로그 전압은 8-bit 아날로그-디지털 변환기를 통해 디지털 데이터로 표시된다. ASK 복조기와 간단한 디지털 회로로 구성된 회로 블록을 이용해 여러 태그 칩 중에 단일 칩을 선택할 수 있는 식별자 정보를 인식할 수 있다. 제작된 온도 센서는 주변 환경 온도 $20^{\circ}C$ to $100^{\circ}C$ 사이의 온도를 측정한 결과, $0.64^{\circ}C/LSB$의 해상도를 나타내었다. 온도 센서 구동에 필요한 입력 전력은 -11 dBm이었고, 온도 오차는 최대 $0.5^{\circ}C$, 칩 면적은 $1.1{\times}0.34mm^2$, 동작주파수는 100 kHz, 전력소모는 64 ${\mu}W$, 변환율은 12.5 k-samples/sec을 가진다.

Keywords

References

  1. E. H. J. Callaway, "Wireless Sensor Networks: Architectures and Protocols," New York: Auerbach, 2004
  2. F. Kocer and M. P. Flynn, "An RF-powered, wireless CMOS temperature sensor," IEEE Sensors Journal, Vol. 6, No. 3, pp. 557-564, 2006 https://doi.org/10.1109/JSEN.2006.874457
  3. 김현식, 조정현, 김시호, "무선 전력 구동 센서 태그 내장형 온도센서의 설계," 전자공학회 논문지 제 44권 제 10호, pp. 831-836, 2007
  4. N. Cho, S. J. Song, S. Kim, S. Kim, and H. J. Yoo, "A 5.1 $\mu$W UHF RFID tag chip integrated with sensors for wireless environmental monitoring," Proc. Eur. Solid-State Circuits Conf. (ESSCIRC), pp. 279-282, 2005
  5. Nhan Tran, Bomson Lee, and Jong.-Wook. Lee, "Development of Long-Range UHF-band RFID Tag chip Using Schottky Diodes in Standard CMOS Technology," IEEE Radio Frequency Integrated Circuit (RFIC) Symposium, 2007, pp. 281-284
  6. Agilent Technologies, Advanced Design System, 2004
  7. G. Giustolisi, G. Palumbo, and F. Cultri, "A low-voltage low-power voltage reference based on subthreshold MOSFETs." IEEE J. Solid-State Circuits, vol. 38, no. 1, pp. 151, 2004 https://doi.org/10.1109/JSSC.2002.806266
  8. J. Baker, CMOS Circuit Design, Layout, and Simulation, IEEE Press Series on Microelectronic Systems, Wiley Interscience
  9. C.-H. Lee and H.-J. Park, "All-CMOS temperature independent current reference," Electron. Lett., vol. 32, no. 14, 1996, pp. 1280 https://doi.org/10.1049/el:19960827
  10. F. Azais, S. Bernard, Y. Betrand, X. Michel, and M. Renovell, "A low-cost adaptive ramp generator for analog BIST applications," IEEE proc. VLSI test Symp., 2001, pp. 266