臺灣博碩士論文加值系統

本論文提出了一個全CMOS組成可調電壓的低功耗溫度感測器，所提出的架構只用一個操作在次臨界區的環形振盪器來感測溫度，因此面積和功耗都比以往的研究要小。感測器的操作電壓範圍從0.6到1.2伏特，因此可和數位電路共用電源而不需要額外的電壓調節器。此外，因為感測器使用面積很小，所以在和數位電路進行標準元件庫設計流程的時候，對時序限制所造成的影響會比一般用ADC做的感測器要小。感測器用0.18μm CMOS製程製作，所佔的面積為0.06 mm^2，室溫下所消耗的功率為55 nW。而在兩點校正之下，準確度能到+0.34°C/-1.97°C。在操作電壓從0.6到1.2伏特，在不重新校正的情況下，誤差可以到+2.23°C/-1.53°C。本論文所提出的感測器架構適合用在IoT系統或有限能源的裝置。

This thesis presents an all CMOS, low power and voltage scalable temperature sensor. The proposed temperature sensor based on only a ring oscillator which operates in subthreshold region to sense temperature, resulting in a smaller area and lower power consumption than previous studies. The sensor can be operated with supply voltage from 0.6 to 1.2 V, so it can share the power grid with digital circuit without additional regulator. Also, since the sensor is compact, placing a sensor inside digital circuits to run the standard cell design flow will have smaller impact on timing constraint compared to conventional ADC-based sensors. The sensor is implemented in 0.18μm CMOS process and occupies 0.06 mm^2 while consuming 55 nW at room temperature. Accuracy of +0.34°C/-1.97°C is achieved after 2-point calibration. Error of +2.23°C/-1.53°C with no recalibration is achieved under supply voltage from 0.6 to 1.2 V. The proposed sensor is suitable for IoT systems or energy-constrained devices.

口試委員會審定書 iii

誌謝 v

摘要 vii

Abstract ix

1 Introduction 1
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Thesis Organization . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 Surveys of Temperature Sensor Architecture 5
2.1 BJT Temperature Sensor. . . . . . . . . . . . . . . . . . . . . . 5
2.2 CMOS Ring Oscillator-based Temperature Sensor . 7
2.3 CMOS Leakage-Current-Based Temperature Sensor. 10
2.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3 Design and Implementation of a Ultra Low Power Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 Ring Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2.1 Back-to-Back Inverters . . . . . . . . . . . . . . . . . . . 19
3.2.2 Transistor Stacking . . . . . . . . . . . . . . . . . . . . . . 21
3.2.3 Operation Principle . . . . . . . . . . . . . . . . . . . . . . 23
3.3 Temperature Sensor Architecture . . . . . . . . . . . . . . 27
3.4 Supply Voltage Scalability . . . . . . . . . . . . . . . . . . . . 29

4 Measurement Results 35

5 Conclusion 43
5.1 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Reference 45

[1] T. Anand, K. A. A. Makinwa, and P. K. Hanumolu, “A VCO Based Highly Digital Temperature Sensor With 0.034°C/mV Supply Sensitivity ,” IEEE Journal of Solid-State Circuits, vol. 51, pp. 2651–2663, Nov 2016.

[2] S. Paek, W. Shin, J. Lee, H. E. Kim, J. S. Park, and L. S. Kim, “Hybrid Temperature Sensor Network for Area-Efficient On-Chip Thermal Map Sensing ,” IEEE Journal of Solid-State Circuits, vol. 50, pp. 610–618, Feb 2015.

[3] W. Huang, M. R. Stan, K. Sankaranarayanan, R. J. Ribando, and K. Skadron, “Manycore design from a thermal perspective ,” in 2008 45th ACM/IEEE Design Automation Conference, pp. 746–749, June 2008.

[4] P. Chundi, Y. Zhou, M. Kim, E. Kursun, and M. Seok, “Hotspot Monitoring and Temperature Estimation with Miniature On-Chip Temperature Sensors ,” in IEEE/ACM International Symposium on Low Power Electronics and Design, 2017.

[5] S. Kim and M. Seok, “A 30.1 µm 2 , < ± 1.1 ◦ C-3σ-error, 0.4-to-1.0V temperature sensor based on direct threshold-voltage sensing for on-chip dense thermal monitoring ,” in 2015 IEEE Custom Integrated Circuits Conference (CICC), pp. 1–4, Sept 2015.

[6] T. Yang, S. Kim, P. R. Kinget, and M. Seok, “Compact and Supply-Voltage-Scalable Temperature Sensors for Dense On-Chip Thermal Monitoring ,” IEEE Journal of Solid-State Circuits, vol. 50, pp. 2773–2785, Nov 2015.

[7] K. Souri, Y. Chae, and K. A. A. Makinwa, “A CMOS Temperature Sensor With a Voltage-Calibrated Inaccuracy of ± 0.15 ◦ C (3σ ) From − 55 ◦ C to 125 ◦ C ,” IEEE Journal of Solid-State Circuits, vol. 48, pp. 292–301, Jan 2013.

[8] M. A. P. Pertijs, K. A. A. Makinwa, and J. H. Huijsing, “A CMOS smart temperature sensor with a 3 σ; inaccuracy of ± 0.1 ◦ C from -55 ◦ C to 125 ◦ C ,” IEEE Journal of Solid-State Circuits, vol. 40, pp. 2805–2815, Dec 2005.

[9] P. Chen, C.-C. Chen, C.-C. Tsai, and W.-F. Lu, “A time-to-digital-converter-based CMOS smart temperature sensor ,” IEEE Journal of Solid-State Circuits, vol. 40, pp. 1642–1648, Aug 2005.

[10] S. Jeong, Z. Foo, Y. Lee, J. Y. Sim, D. Blaauw, and D. Sylvester, “A Fully-Integrated 71 nW CMOS Temperature Sensor for Low Power Wireless Sensor Nodes ,” IEEE Journal of Solid-State Circuits, vol. 49, pp. 1682–1693, Aug. 2014.

[11] N. Retdian, S. Takagi, and N. Fujii, “Voltage controlled ring oscillator with wide tuning range and fast voltage swing ,” in Proceedings. IEEE Asia-Pacific Conference on ASIC,, pp. 201–204, 2002.

[12] K. Yang, Q. Dong, W. Jung, Y. Zhang, M. Choi, D. Blaauw, and D. Sylvester, “9.2 A 0.6nJ −0.22/+0.19°C Inaccuracy Temperature Sensor Using Exponential Subthreshold Oscillation Dependence ,” in 2017 IEEE International Solid-State Circuits Conference (ISSCC), pp. 160–161, Feb 2017.

[13] E. Saneyoshi, K. Nose, M. Kajita, and M. Mizuno, “A 1.1V 35μm × 35μm thermal sensor with supply voltage sensitivity of 2°C/10management on the SX-9 supercomputer ,” in 2008 IEEE Symposium on VLSI Circuits, pp. 152–153, June 2008.

[14] I. Lee, D. Sylvester, and D. Blaauw, “A Constant Energy-Per-Cycle Ring Oscillator Over a Wide Frequency Range for Wireless Sensor Nodes ,” IEEE Journal of Solid-State Circuits, vol. 51, pp. 697–711, March 2016.

[15] S. Narendra, S. Borkar, V. De, D. Antoniadis, and A. Chandrakasan, “Scaling of stack effect and its application for leakage reduction ,” in Low Power Electronics and Design, International Symposium on, 2001., pp. 195–200, 2001.

[16] R. Rao, A. Srivastava, D. Blaauw, and D. Sylvester, “Statistical analysis of subthreshold leakage current for VLSI circuits ,” IEEE Transactions on Very Large Scale Integration (VLSI) Systems, vol. 12, pp. 131–139, Feb 2004.

[17] I. M. Filanovsky and A. Allam, “Mutual compensation of mobility and threshold voltage temperature effects with applications in CMOS circuits ,” IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications, vol. 48, pp. 876884, Jul 2001.

[18] R. Kumar and V. Kursun, “Reversed Temperature-Dependent Propagation Delay Characteristics in Nanometer CMOS Circuits ,” IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 53, pp. 1078–1082, Oct 2006.

[19] A. K. M. M. Islam, J. Shiomi, T. Ishihara, and H. Onodera, “Wide-Supply-Range AllDigital Leakage Variation Sensor for On-Chip Process and Temperature Monitoring ,” IEEE Journal of Solid-State Circuits, vol. 50, pp. 2475–2490, Nov 2015.

[20] H. Lakdawala, Y. W. Li, A. Raychowdhury, G. Taylor, and K. Soumyanath, “A 1.05 V 1.6 mW, 0.45 ◦ C 3σ Resolution Σ∆ Based Temperature Sensor With Parasitic Resistance Compensation in 32 nm Digital CMOS Process ,” IEEE Journal of Solid-State Circuits, vol. 44, pp. 3621–3630, Dec 2009.