Time-Domain Smart Temperature Sensor Using Current Starved Inverters and Switched Ring Oscillator-Based Time-to-Digital Converter

  • R. S. S. M. R. KrishnaEmail author
  • Ashis Kumar Mal
  • Rajat Mahapatra


This article reports a time-domain smart temperature sensor using current starved inverters (CSIs) and switched ring oscillator-based time-to-digital converter (SRO-TDC) in a standard \({180} \hbox { nm}\) CMOS process. A novel temperature-to-time converter (TTC) is proposed using complementary delay lines, which are designed by utilising CSIs. The proportional to absolute temperature delay line offers a temperature coefficient (TC) of 615 ppm/\(^{\circ }\hbox {C}\), whereas the complementary to absolute temperature delay line possesses a TC of 300 ppm/\(^{\circ }\hbox {C}\), over 0–100 \(^{\circ }\hbox {C}\) temperature range. A novel multipath delay cell-based coupled oscillator is proposed for SRO-TDC. The proposed SRO-TDC operates as readout circuit for the sensor, which achieves 30 ns range at 12 ps resolution. The uncertainty of the sensor is limited to \(\pm \,0.63\,^{\circ }\hbox {C}\), after the 2-point calibration at \(20\,^{\circ }\hbox {C}\) and \(80\,^{\circ }\hbox {C}\), which is because of complementary delay lines in TTC and noise shaping behaviour of the SRO-TDC. The sensor achieves \(0.4\,\upmu \hbox {s}\) conversion time at \(0.04\,^{\circ }\hbox {C}\) resolution.


Time-domain sensor Smart temperature sensor Current starved inverter (CSI) Temperature-to-time converter (TTC) Switched ring oscillator (SRO) Time-to-digital converter (TDC) Multipath delay cell Dynamic element matching (DEM) Uncertainty Calibration 



This research was supported in part by Visvesvaraya PhD Scheme for Electronics & IT, MeitY, Govt. of India, Grant No. PhDMLA/4(29)/2015-16/01 and Special Manpower Development Programme for Chips-to-System Design, MeitY, Govt. of India, Grant No. 9(1)/2014-MDD (Vol III). Semi-Conductor Laboratory, Department of Space, Government of India, is acknowledged for valuable support. Amrita Dikshit is also acknowledged for her contribution.


  1. 1.
    P.E. Allen, D. Holberg, CMOS Analog Circuit Design (Oxford University Press, Oxford, 2012)Google Scholar
  2. 2.
    R. Baird, T. Fiez, Linearity enhancement of multibit $\Delta \Sigma $ A/D and D/A converters using data weighted averaging. IEEE Trans. Circuits Syst. II Analog Digit. Signal Process. 42(12), 753–762 (1995)CrossRefGoogle Scholar
  3. 3.
    R.J. Baker, CMOS: Circuit Design, Layout, and Simulation (Wiley, Hoboken, 2010)CrossRefGoogle Scholar
  4. 4.
    C.C. Chen, C.L. Chen, Y. Lin, S.Q. You, An all-digital time-domain smart temperature sensor with a cost-efficient curvature correction. IEEE Trans. Very Large Scale Integr. (VLSI) Syst. 27(1), 29–36 (2019)CrossRefGoogle Scholar
  5. 5.
    P. Chen, C.-C. Chen, C.-C. Tsai, L. Wen-Fu, A time-to-digital-converter-based CMOS smart temperature sensor. IEEE J. Solid-State Circuits 40(8), 1642–1648 (2005)CrossRefGoogle Scholar
  6. 6.
    R. Dastanian, E. Abiri, M. Ataiyan, A 0.5 V, 112 nW CMOS temperature sensor for RFID food monitoring application. Iran. J. Sci. Technol. Trans. Electr. Eng. 41(2), 145–152 (2017)CrossRefGoogle Scholar
  7. 7.
    A. Elshazly, S. Rao, B. Young, P.K. Hanumolu, A noise-shaping time-to-digital converter using switched-ring oscillators-analysis, design, and measurement techniques. IEEE J. Solid-State Circuits 49(5), 1184–1197 (2014)CrossRefGoogle Scholar
  8. 8.
    D. Ha, K. Woo, S. Meninger, T. Xanthopoulos, E. Crain, D. Ham, Time-domain CMOS temperature sensors with dual delay-locked loops for microprocessor thermal monitoring. IEEE Trans. Very Large Scale Integr. (VLSI) Syst. 20(9), 1590–1601 (2012)CrossRefGoogle Scholar
  9. 9.
    M. Heidarpour Roshan, S. Zaliasl, K. Joo, K. Souri, R. Palwai, L.W. Chen, A. Singh, S. Pamarti, N.J. Miller, J.C. Doll, C. Arft, S. Tabatabaei, C. Sechen, A. Partridge, V. Menon, A MEMS-assisted temperature sensor with 20-$\mu K$ resolution, conversion rate of 200 S/s, and FOM of 0.04 pJK$^{2}$. IEEE J. Solid-State Circuits 52(1), 185–197 (2017)CrossRefGoogle Scholar
  10. 10.
    Q. Huang, H. Joo, J. Kim, C. Zhan, J. Burm, An energy-efficient frequency-domain CMOS temperature sensor with switched vernier time-to-digital conversion. IEEE Sens. J. 17(10), 3001–3011 (2017)CrossRefGoogle Scholar
  11. 11.
    S. Hwang, J. Koo, K. Kim, H. Lee, C. Kim, A 0.008 ${\text{ mm }}^{2}$ 500 $\mu {\rm W}$ 469 kS/s frequency-to-digital converter based CMOS temperature sensor with process variation compensation. IEEE Trans. Circuits Syst. I Regul. Pap. 60(9), 2241–2248 (2013)CrossRefGoogle Scholar
  12. 12.
    K. Kim, H. Lee, S. Jung, C. Kim, A 366 kS/s 400 $\mu $W 0.0013 mm$^2$ frequency-to-digital converter based CMOS temperature sensor utilizing multiphase clock, in 2009 IEEE Custom Integrated Circuits Conference (IEEE, 2009), pp. 203–206Google Scholar
  13. 13.
    H. Lakdawala, Y.W. Li, A. Raychowdhury, G. Taylor, K. Soumyanath, A 1.05 V 1.6 mW, 0.45 $^{\circ }$C 3$\sigma $ resolution $\Sigma \Delta $ based temperature sensor with parasitic resistance compensation in 32 nm digital CMOS process. IEEE J. Solid-State Circuits 44(12), 3621–3630 (2009)CrossRefGoogle Scholar
  14. 14.
    M. Lee, A.A. Abidi, A 9 b, 1.25 ps resolution coarse-fine time-to-digital converter in 90 nm CMOS that amplifies a time residue. IEEE J. Solid-State Circuits 43(4), 769–777 (2008)CrossRefGoogle Scholar
  15. 15.
    J. Maneatis, M. Horowitz, Precise delay generation using coupled oscillators. IEEE J. Solid-State Circuits 28(12), 1273–1282 (1993)CrossRefGoogle Scholar
  16. 16.
    J. Marin, E. Sacco, J. Vergauwen, G. Gielen, A single-temperature-calibration 0.18-$\mu $m CMOS time-based resistive sensor interface with low drift over a -40 $^{\circ }$C to 175 $^{\circ }$C temperature range, in ESSCIRC 2018—IEEE 44th European Solid State Circuits Conference (ESSCIRC) (IEEE, 2018), pp. 330–333Google Scholar
  17. 17.
    S. Pan, K.A.A. Makinwa, A 0.25 mm$^2$-resistor-based temperature sensor with an inaccuracy of 0.12 $^{\circ }$C (3$\sigma $) from $-55~^{\circ }$C to 125 $^{\circ }$C. IEEE J. Solid-State Circuits 53(12), 3347–3355 (2018)CrossRefGoogle Scholar
  18. 18.
    S. Pan, K.A.A. Makinwa, Energy-efficient high-resolution resistor-based temperature sensors, in Hybrid ADCs, Smart Sensors for the IoT, and Sub-1V & Advanced Node Analog Circuit Design: Advances in Analog Circuit Design 2017, ed. by P. Harpe, K.A.A. Makinwa, A. Baschirotto (Springer International Publishing, Cham, 2018), pp. 183–200CrossRefGoogle Scholar
  19. 19.
    J.H. Park, D.H. Jung, S.O. Jung, GRO-TDC with gate-switch-based delay cell halving resolution limit. Int. J. Circuit Theory Appl. 45(12), 2211–2225 (2017)CrossRefGoogle Scholar
  20. 20.
    S. Pavan, R. Schreier, G.C. Temes, Understanding Delta-Sigma Data Converters (Wiley, New York, 2017)Google Scholar
  21. 21.
    T. Someya, A.K.M.M. Islam, T. Sakurai, M. Takamiya, An 11-nW CMOS temperature-to-digital converter utilizing sub-threshold current at sub-thermal drain voltage. IEEE J. Solid-State Circuits 54(3), 613–622 (2019)CrossRefGoogle Scholar
  22. 22.
    W. Song, J. Lee, N. Cho, J. Burm, An ultralow power time-domain temperature sensor with time-domain delta-sigma TDC. IEEE Trans. Circuits Syst. II Express Briefs 64(10), 1117–1121 (2017)CrossRefGoogle Scholar
  23. 23.
    U. Sonmez, F. Sebastiano, K.A.A. Makinwa, Compact thermal-diffusivity-based temperature sensors in 40-nm CMOS for SoC thermal monitoring. IEEE J. Solid-State Circuits 52(3), 834–843 (2017)CrossRefGoogle Scholar
  24. 24.
    K. Souri, Y. Chae, K.A.A. Makinwa, A CMOS temperature sensor with a voltage-calibrated inaccuracy of $\pm $0.15$^{\circ }$C (3$\sigma $) from $-55^{\circ }$C to 125$^{\circ }$C. IEEE J. Solid-State Circuits 48(1), 292–301 (2013)CrossRefGoogle Scholar
  25. 25.
    K. Souri, K.A.A. Makinwa, A 0.12 mm$^{2}$ 7.4 $\mu $W micropower temperature sensor with an inaccuracy of $\pm $0.2$^{\circ }$C (3$\sigma $) from $-30^{\circ }$C to 125$^{\circ }$C. IEEE J. Solid-State Circuits 46(7), 1693–1700 (2011)CrossRefGoogle Scholar
  26. 26.
    Z. Tang, Y. Fang, X.P. Yu, Z. Shi, N. Tan, A CMOS temperature sensor with versatile readout scheme and high accuracy for multi-sensor systems. IEEE Trans. Circuits Syst. I Regul. Pap. 65(11), 3821–3829 (2018)CrossRefGoogle Scholar
  27. 27.
    Y. Tsividis, C. McAndrew, Operation and Modeling of the MOS Transistor (Oxford University Press, Oxford, 2011)Google Scholar
  28. 28.
    H. Xin, M. Andraud, P. Baltus, E. Cantatore, P. Harpe, A 174 pW–488.3 nW 1 S/s–100 kS/s all-dynamic resistive temperature sensor with speed/resolution/resistance adaptability. IEEE Solid-State Circuits Lett. 1(3), 70–73 (2018)CrossRefGoogle Scholar
  29. 29.
    F. Yuan, CMOS Time-Mode Circuits and Systems (CRC Press, Cambridge, 2015)CrossRefGoogle Scholar
  30. 30.
    D. Zhu, L. Siek, A 0.058 mm$^{2}$ 24 $\mu $W temperature sensor in 40-nm CMOS process with $\pm $0.5 $^{\circ }$C inaccuracy from $-55~^{\circ }$C to 175 $^{\circ }$C. Circuits Syst. Signal Process. 37(6), 2278–2298 (2018)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of ECENIT DurgapurDurgapurIndia

Personalised recommendations