Publications, Patents, Invited Talks

Summary

• 1 book chapter

• 41 journal articles

• 57 conference papers

Book Chapters

1. I. Lee and Y. Lee, “Circuit Design in mm-Scale Sensor Platform for Future IoT Applications,” Chapter in Smart Sensors and Systems, C.-M. Kyung, H. Yasuura, Y. Liu, and Y.-L. Lin, editors, Springer Publishing Company, 2017. doi: https://doi.org/10.1007/978-3-319-33201-7_3

Journal Articles

1. E. A. Hamed, S. Muloor, I. Lee, “Low-Power Digital Temperature Compensation Technique for XO Wake-Up Timers, IEEE Transactions on Very Large Scale Integration (VLSI) Systems, accepted.

2. M. Shim, E. A. Hamed, Y. Li, W. Seok, S. Jeong, Y. Kim, W. Jung, and I. Lee, “Low-Power Power Management Unit with Adaptive Dynamic Load Power Tracking for Millimeter-Scale Computing Systems,” IEEE Transactions on Power Electronics (TPEL), accepted. doi: https://doi.org/10.1109/TPEL.2025.3604695

3. Y. Ji, Y. Li, and I. Lee, "Low-Power Subthreshold Voltage References for High-Temperature Applications," IEEE Transactions on Circuits and Systems I: Regular Papers (TCAS-I), vol. 72, no. 6, pp. 2529-2542, June 2025. doi: https://doi.org/10.1109/TCSI.2025.3554367

4. E. A. Hamed, G. Carichner, D. A. Green, H. -S. Kim and I. Lee, "Hybrid Timestamping Using Crystal and RC Oscillators for Shock-Resistant Precision," IEEE Transactions on Very Large Scale Integration (VLSI) Systems, vol. 33, no. 7, pp. 2004-2008, Mar. 2025. doi: https://doi.org/10.1109/TVLSI.2025.3544410

5. Y. Li, R. Caginalp, and I. Lee, "A Picowatt CMOS Voltage Reference Using Independent TC and Output Level Calibrations," IEEE Transactions on Very Large Scale Integration (VLSI) Systems, vol. 33, no. 5, pp. 1244-1254, May 2025. doi: https://doi.org/10.1109/TVLSI.2024.3508259

6. H. Eum, K. A. A. Makinwa, I. Lee and Y. Chae, "A Sub-1-V Capacitively-Biased Voltage Reference With an Auto-Zeroed Buffer and a TC of 18-ppm/° C," IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 72, no. 1, pp. 8-12, Jan. 2025. doi: https://doi.org/10.1109/TCSII.2024.3454348

7. Y. Li, V. S. Vivekanand, R. Kubendran and I. Lee, "Dynamic Neural Fields Accelerator Design for a Millimeter-Scale Tracking System," IEEE Transactions on Very Large Scale Integration (VLSI) Systems, vol. 32, no. 10, pp. 1940-1944, Oct. 2024. doi: https://doi.org/10.1109/TVLSI.2024.3416725

8. H. Lee, D. Seo, J. Woo, Y. Lee, I. Lee*, and Y. Chae*, “A 23.9-μW 13.6-Bit Period Modulation-Based Capacitance-to-Digital Converter With Dynamic Current Mirror Front-End,” IEEE Solid-State Circuits Letters (SSCL), vol. 7, pp. 135-138, Mar. 2024.  doi: https://doi.org/10.1109/LSSC.2024.3382813 (* Co-corresponding author) (Invited)

9. Y. Li, Y. Kim and I. Lee, "A 5-mm2, 4.7- uW Convolutional Neural Network Layer Accelerator for Miniature Systems," IEEE Transactions on Very Large Scale Integration Systems (TVLSI), vol. 31, no. 12, pp. 2142-2146, Dec. 2023. doi: https://doi.org/10.1109/TVLSI.2023.3324572

10. D. Seo, M. Cho, M. Jeong, G. Shin, I. Lee, D. Blaauw, and Y. Lee, "An RC Delay-Based Pressure-Sensing System with Energy-Efficient Bit-Level Oversampling Techniques for Implantable IOP Monitoring Systems," IEEE J. Solid-State Circuits (JSSC), vol. 58, no. 10, pp. 2745-2756, June 2023. doi: https://doi.org/10.1109/JSSC.2023.3286796 (Invited)

11. H.-Y. Lee, C Lee, I. Lee, and Y. Chae, "A 0.033-mm2 21.5-to-119.4-aF Resolution Continuous-Time ΔΣ Capacitance-to-Digital Converter Achieving Parasitic Capacitance Immunity up to 480-pF," IEEE J. Solid-State Circuits (JSSC), vol. 57, no. 10, pp. 3048-3057, Oct. 2022. doi: https://doi.org/10.1109/JSSC.2022.3184531  (Invited)

12. Y. Li, Y. Wu, X. Zhang, J. Hu, and I. Lee, "Energy-Aware Adaptive Multi-Exit Neural Network Inference Implementation for a Millimeter-Scale Sensing System," IEEE Transactions on Very Large Scale Integration Systems (TVLSI), vol 30, no. 7, pp 849-859, July 2022. doi: https://doi.org/10.1109/TVLSI.2022.3171308

13. E. A. Hamed*, J. Athas*, X. Zhang, N. Ashenden, and I. Lee, "A Low-Power GPIO-Based Size Sensor to Monitor the Imbibition of Corn Seeds Beneath Soil," MDPI Electronics, vol. 10, no. 19, Oct. 2021 (* equally contributed). doi: https://doi.org/10.3390/electronics10192423

14. Y. Li*, Y. Gao*, M. Shao, J. T. Tonecha, Y. Wu, J. Hu, and I. Lee, "Implementation of Multi-Exit Neural-Network Inferences for an Image-Based Sensing System with Energy Harvesting," MDPI Journal of Low Power Electronic Application (JLPEA), vol. 11, no. 3, Sep. 2021 (* equally contributed). doi: https://doi.org/10.3390/jlpea11030034

15. E. A. Hamed and I. Lee, "Categorization and SEU Fault Simulations of Radiation-Hardened-by-Design Flip-Flops," MDPI Electronics, vol. 10, no. 13, June 2021. doi: https://doi.org/10.3390/electronics10131572

16. C. S. Bick*, I. Lee*, D. Blaauw, T. Coote, A. E. Haponski, and D. Ó Foighil, “Millimeter-sized smart sensors reveal that a solar refuge protects tree snail Partula hyalina from extirpation,” Communication Biology, vol. 4, no. 1, p. 744, June 2021. doi: https://doi.org/10.1038/s42003-021-02124-y (* equally contributed).

17. Y. Li, Y. E. A. Hamed, X. Zhang, D. Luna, J.-S. Lin, X. Liang, I. Lee, "Feasibility of Harvesting Solar Energy for Self-Powered Environmental Wireless Sensor Nodes," MDPI Electronics, vol. 9, no. 12, Dec. 2020. doi: https://doi.org/10.3390/electronics9122058

18. Y. Peng, K. D. Choo, S. Oh, I. Lee, T. Jang, Y. Kim, J. Lim, D. Blaauw, and D. Sylvester, “An Efficient Piezoelectric Energy Harvesting Interface Circuit Using a Sense-and-Set Rectifier,” IEEE J. Solid-State Circuits, vol. 54, no. 12, pp. 3348-3361, Dec. 2019. doi: https://doi.org/10.1109/JSSC.2019.2945262 (Invited)

19. P. Bollella, I. Lee, D. Blaauw, and E. Katz, “A Microelectronic Sensor Device Powered by a Small Implantable Biofuel Cell,” ChemPhysChem, Aug. 2019. doi: https://doi.org/10.1002/cphc.201900700 (* equally contributed) (Highlighted as a very important paper).

20. E. Moon, I. Lee, D. Blaauw, and J. Phillips, “High-Efficiency Photovoltaic Modules on a Chip for Millimeter-Scale Energy Harvesting,” Progress in Photovoltaics: Research and Applications, vol 27, no. 6, pp 540-546, Mar. 2019. doi: https://doi.org/10.1002/pip.3132

21. M. Gamella*, I. Lee*, N. Guz, D. Blaauw, and E. Katz, “Bioelectronic Interface between Biomolecular Logic Systems and microelectronics,” International Journal of Unconvnetional Computing, vol. 14, no. 1, pp 27-41, Jan. 2018. doi: N/A (https://www.oldcitypublishing.com/journals/ijuc-home/ijuc-issue-contents/ijuc-volume-14-number-1-2018/ijuc-14-1-p-27-41/) (* equally contributed)

22. M. Choi, Y. Sui, I. H. Lee, Ryan Meredith, Y. Ma, G. Kim, D. Blaauw, Y. B. Gianchandani, and T. Li, “Autonomous Microsystems for Downhole Applications: Design Challenges, Current State, and initial Test Results,” MDPI Sensors, vol. 17, Sep. 2017. doi: https://doi.org/10.3390/s17102190

23. I. Lee, S. Bang, Y. Kim, G. Kim, D. Sylvester, D. Blaauw, and Y. Lee, “A Wire-overhead-free Reset Propagation Scheme for Millimeter-scale Sensor Systems,” J. Semiconductor Technology and Science, vol. 17, no. 4, pp 524-533, Aug. 2017. doi: https://doi.org/10.5573/JSTS.2017.17.4.524

24.  I. Lee, D. Sylvester, and D. Blaauw, “A Subthreshold Voltage Reference With Scalable Output Voltage for Low-Power IoT Systems,” IEEE J. Solid-State Circuits, vol. 52, no. 5, pp. 1443-1449, May. 2017. doi: https://doi.org/10.1109/JSSC.2017.2654326

25. X. Wu, Y. Shi, S. Jeloka, K. Yang, I. Lee, Y. Lee, D. Sylvester, and D. Blaauw, “A 20-pW Discontinuous Switched-Capacitor Energy Harvester for Smart Sensor Applications,” IEEE J. Solid-State Circuits, vol. 52, no. 4, pp. 972-984, Apr. 2017. doi: https://doi.org/10.1109/JSSC.2016.2645741 (Invited).

26. I. Lee, Y-S Kuo, P. Pannuto, G. Kim, Z. Foo, B. Kempke, S. Jeong, Y. Kim, P. Dutta, D. Blaauw, and Y. Lee, “MBus: A Fully Synthesizable Low-power Portable Interconnect Bus for Millimeter-scale Sensor Systems,” J. Semiconductor Technology and Science, vol. 16, no. 6, pp 745-753, Dec. 2016. doi: https://doi.org/10.5573/JSTS.2016.16.6.745

27. I. Lee, Y. Lee, D. Sylvester, and D. Blaauw, “Battery Voltage Supervisors for Miniature IoT Systems,” IEEE J. Solid-State Circuits, vol. 51, no. 11, pp. 2743-2756, Nov. 2016. doi: https://doi.org/10.1109/JSSC.2016.2600565

28. S. Teran, E. Moon, W. Lim, G. Kim, I. Lee, D. Blaauw, and J. D. Phillips, “Energy Harvesting for GaAs Photovoltaics Under Low-Flux Indoor Lighting Conditions,” IEEE Tran. Electron Devices, vol. 63, no 7, pp. 2820-2825, Jul. 2016. doi: https://doi.org/10.1109/TED.2016.2569079

29. I. Lee, D. Sylvester, and D. Blaauw, “A Constant Energy-Per-Cycle Ring Oscillator Over a Wide Frequency Range for Wireless Sensor Nodes,” IEEE J. Solid-State Circuits, vol. 51, no. 3, pp. 697-711, Mar. 2016. doi: https://doi.org/10.1109/JSSC.2016.2517133

30. S. Jeong, I. Lee, D. Blaauw, and D. Sylvester, “A 5.8 nW CMOS Wake-Up Timer for Ultra-Low-Power Wireless Applications,” IEEE J. Solid-State Circuits, vol. 50, no. 8, pp. 1754-1763, Aug. 2015. doi:  https://doi.org/10.1109/JSSC.2015.2413133 (Invited)

31. I. Lee, G. Kim, S. Bang, A. Wolfe, R. Bell, S. Jeong, Y. Kim, J. Kagan, M. Arias-Thode, B. Chadwick, D. Sylvester, D. Blaauw, and Y. Lee, “System-on-Mud: Ultra-Low Power Oceanic Sensing Platform Powered by Small-Scale Benthic Microbial Fuel Cells,” IEEE Tran. Circuits Syst. I, vol. 62, no. 4, pp 1126-1135, Apr. 2015. doi: https://doi.org/10.1109/TCSI.2015.2390559

32. I. Lee, G. Han, and Y. Chae, “A 2mW, 50 dB DR, 10 MHz BW 5Í Interleaved Bandpass Delta-Sigma Modulator at 50MHz IF,” IEEE Tran. Circuits Syst. I, vol. 62, no. 1, pp. 80-89, Jan. 2015. doi: https://doi.org/10.1109/TCSI.2014.2347234

33. Y. Chen, D. Jeon, Y. Lee, Y. Kim, Z. Foo, I. Lee, N. B. Langhals, G. Kruger, H. Oral, O. Berenfeld, Z. Zhang, D. Blaauw, and D. Sylvester, “An Injectable 64 nW ECG Mixed-Signal SoC in 65 nm for Arrhythmia Monitoring,” IEEE J. Solid-State Circuits, vol. 50, no. 1, pp. 375-390, Jan. 2015. doi:  https://doi.org/10.1109/JSSC.2014.2364036 (Invited)

34. Jeon, M. B. Henry, Y. Kim, I. Lee, Z. Zhang, D. Blaauw, D. Sylvester, “An Energy Efficient Full-Frame Feature Extraction Accelerator With Shift-Latch FIFO in 28 nm CMOS,” IEEE J. Solid-State Circuits, vol. 49, no. 5, pp. 1271-1284, May 2014. doi: https://doi.org/10.1109/JSSC.2014.2309692

35. M. H. Ghead, G. Chen, R. Haque, M. Wieckowski, Y. Kim, G. Kim, Y. Lee, I. Lee, D. Fick, D. Kim, M. Seok, K. D. Wise, D. Blaauw, and D. Sylvester, “Circuits for a Cubic-Millimeter Energy-Autonomous Wireless Intraocular Pressure Monitor,” IEEE Tran. Circuits Syst. I, vol. 60, no. 12, pp. 3152-3162, Dec. 2013. doi: https://doi.org/10.1109/TCSI.2013.2265973

36. Z. Foo, D. M Devescery, M. Hassan, I. Lee, A. Madhavan, Y. S. Park, A. S. Rao, Z. Renner, N. E. Roberts, A. D. Schulman, V. S. Vinay, M. Wieckowski, D. Yoon, C. Schmidt, T. Schmid, P. Dutta, P. M. Chen, and D. Blaauw, "A Low-Cost Audio Computer for Information Dissemination Among Illiterate People Groups," IEEE Tran. Circuits Syst. I, vol. 60, no. 8, pp. 2039-2050, Aug. 2013. doi: https://doi.org/10.1109/CICC.2012.6330652 (Invited)

37. Y. Lee, S. Bang, I. Lee, Y. Kim, G. Kim, Mohammad G., Pat G, P. Dutta, D. Sylvester, and D. Blaauw, "A Modular 1 mm3 Die-Stacked Sensing Platform With Low Power I2C Inter-Die Communication and Multi-Modal Energy Harvesting," IEEE J. Solid-State Circuits, vol. 48, no. 1, pp. 229-243, Jan. 2013. doi: https://doi.org/10.1109/JSSC.2012.2221233 (Invited).

38. J. Cheon, Y. Chae, D. Kim, S. Lim, I. Lee, H.-K Lee, D J. Kim, and G. Han, “Smart CMOS Image Sensor With High SBR and Subpixel Resolution for Light-Section-Based Range Finding,” IEEE Trans. Electron Devices (T-ED), vol. 56, no. 11, pp. 2546-2555, Nov. 2009. doi: https://doi.org/10.1109/TED.2009.2030708

39. J. Cheon, J. Lee, I. Lee, Y. Chae, Y. Yoo, and G. Han, “A Single-Chip CMOS Smoke and Temperature Sensor for an Intelligent Fire Detector,” IEEE Sensors Journal, vol. 9, no. 8, pp.914-921, Aug. 2009. doi: https://doi.org/10.1109/JSEN.2009.2024703

40. I. Lee, R. Hsiao, Gordy Carichner, C.-W. Hsu, M. Wang, S. Shoouri, K. Ernst, T. Carichner, Y. Li, J. Lim, C. R. Julick. E. Moon, Y. Sun, J. Phillips, K. L. Montooth, D. A. Green II, H.-S. Kim, and D. Blaauw, "mSAIL: Milligram-Scale Multi-Modal Sensor Platform for Monarch Butterfly Migration Tracking," Communication of the ACM (CACM), vol. 67, no. 6, pp. 93-101, June 2024. dio: https://doi.org/10.1145/3611105  (Invited) 

41. I. Lee*, R. Hsiao*, Gordy Carichner, C.-W. Hsu, M. Wang, S. Shoouri, K. Ernst, T. Carichner, Y. Li, J. Lim, C. R. Julick. E. Moon, Y. Sun, J. Phillips, K. L. Montooth, D. A. Green II, H.-S. Kim, and D. Blaauw, "Tracking the Migration of the Monarch Butterflies with the World’s Smallest Computer," GetMobile: Mobile Comp. and Comm., vol. 26, no. 1, Mar. 2022 (*equally contributed). doi: https://doi.org/10.1145/3539668.3539677

Conference Papers

1. K. Jeong, C. Livanelioglu, J. Liao, I. Lee and T. Jang, "A 3.47 NEF 175.2dB FOMs Direct Digitization Front-End Featuring Delta Amplification for Enhanced Dynamic Range and Energy Efficiency in Bio-Signal Acquisition," IEEE International Solid-State Circuits Conference (ISSCC), Feb. 2025, San Francisco, CA, USA. doi: https://doi.org/10.1109/ISSCC49661.2025.10904745

2. M. Kim, M. Jeong, D. Seo, Y. Lee, and I. Lee, “A Continuously-Scalable-Conversion-Ratio SC Energy-Harvesting Interface with Exponential DCO for Wide Range Output Power Tracking,” IEEE European Solid-State Electronics Research Conference (ESSERC), Sep. 2024, Bruges, Belgium. doi: https://doi.org/10.1109/ESSERC62670.2024.10719400

3. A. Jain, A. Ali, E. Abhishek, I. Lee, and Z. Abbas, “A 100-Hz, 2nW RC Oscillator Using Resistance Amplifier,” IEEE European Solid-State Electronics Research Conference (ESSERC), Sep. 2024, Bruges, Belgium. doi: https://doi.org/10.1109/ESSERC62670.2024.10719552

4. H. Lee, D. Seo, Y. Woo. Y. Lee, I. Lee, and Y. Chae, “A 23.9 µW 13.6-Bit Period Modulation-Based Capacitance-to-Digital Converter with Dynamic Current Mirror Front-End Achieving Capacitor Range of 1 to 68 pF,” IEEE Asian Solid-State Circuits Conference (ASSCC), Nov. 2023, Haikou, China. doi: https://doi.org/10.1109/A-SSCC58667.2023.10347985

5. A. Dey, A. Ali, A. Jain, I. Lee, and Z. Abbas, “A 162nW, 0.845pJ/step Resistance-to-Digital Converter for Miniature Battery-Powered Sensing Systems,” IEEE International Symposium on Circuit and Systems (ISCAS), May 2023, Monterey, CA, USA. doi: https://doi.org/10.1109/ISCAS46773.2023.10181881

6. S. Agarwal, S. B. Yerragudi, N. Dasarai, I. Lee, and Z. Abbas, “An 18.5nW, 62.9dB PSRR, Switched-Capacitor Bandgap Voltage Reference using Low Power Clock Generator Circuit for Biomedical Applications,” IEEE International Symposium on Circuit and Systems (ISCAS), May 2023, Monterey, CA, USA. doi: https://doi.org/10.1109/ISCAS46773.2023.10181473

7. B. Sahishnavi, S. Kumar, A. Ali, A. Dey, I. Lee, and Z. Abbas, “A 0.5V, pico-watt, 0.06%/V / 0.03%/V low supply sensitive current/voltage reference without using amplifiers and resistors,” IEEE International Symposium on Circuit and Systems (ISCAS), May 2023, Monterey, CA, USA. doi: https://doi.org/10.1109/ISCAS46773.2023.10181479

8. A. Huluvallay*, A. Pullela*, E. A. Hamed*, A. Jain, N. Daasari, Z. Abbas, and I. Lee, “A 7 nW, 1 kHz, -40 – 170 °C Relaxation Oscillator with Switch-Leakage Compensation for Low-Power High-Temperature IoT Systems,” IEEE International Symposium on Circuit and Systems (ISCAS), May 2023, Monterey, CA, USA. doi: https://doi.org/10.1109/ISCAS46773.2023.10181807 (* equally contributed)

9. D. Seo, M. Cho, M. Jeong, G. Shin, I. Lee, and Y. Lee, "A 0.24 mmHg (1σ) Resolution Half-Bridge-to-Digital Converter with RC Delay-Based Pressure Sensing and Energy-Efficient Bit-Level Oversampling Techniques for Implantable Miniature Systems," IEEE Asian Solid-State Circuits Conference (ASSCC), Nov. 2022, Taipei, Taiwan. doi: https://doi.org/10.1109/A-SSCC56115.2022.9980628

10. Y. Li and I. Lee, "A 36pW CMOS Voltage Reference With Independent TC and Output Level Calibration for Miniature Low-Power Systems," IEEE International Symposium on Circuit and Systems (ISCAS), June 2022, Austin, TX, USA. doi: https://doi.org/10.1109/ISCAS48785.2022.9937312

11. V. Pullela, A. Huluvallay, A. Jain, I. Lee, and Z. Abbas "A 156pW Gate-Leakage Based Voltage/Current Reference for Low-Power IoT Systems," IEEE International Symposium on Circuit and Systems (ISCAS), June 2022, Austin, TX, USA. doi: https://doi.org/10.1109/ISCAS48785.2022.9937316

12. S. Shoouri, M. Yang, G. Carichner, Y. Li, E. A. Hamed, A. Deng, D. A. Green, I. Lee, D. Blaauw, and H.-S. Kim, “Siamese Learning-Based Monarch Butterfly Localization,” IEEE Data Science and Learning Workshop (DSLW), May 2022, Singapore, Singapore. doi: https://doi.org/10.1109/DSLW53931.2022.9820497

13. I. Lee*, R. Hsiao*, Gordy Carichner, C.-W. Hsu, M. Wang, S. Shoouri, K. Ernst, T. Carichner, Y. Li, J. Lim, C. R. Julick. E. Moon, Y. Sun, J. Phillips, K. L. Montooth, D. A. Green II, H.-S. Kim, and D. Blaauw, "mSAIL: Milligram-Scale Multi-Modal Sensor Platform for Monarch Butterfly Migration Tracking," ACM International Conference on Mobile Computing and Networking (MobiCom), Oct. 2021, New Orleans, LA, USA. doi: https://doi.org/10.1145/3447993.3483263 (* equally contributed) (Best paper award)

14. S. Jeong, Y. Kim, Y. Li, and I. Lee, "A Millimeter-Scale Computing System with Adaptive Dynamic Load Power Tracking," IEEE Asian Solid-State Circuits Conference (ASSCC), Nov. 2021, Busan, South Korea. doi: https://doi.org/10.1109/A-SSCC53895.2021.9634758

15. Y. Li, E. Moon, J. Phillips, and I. Lee, "A Stacked-Photovoltaic-Cell Energy Harvester with >81% Indoor Light Harvesting Efficiency for Millimeter-Scale Energy-Autonomous Sensor Nodes," IEEE European Solid-State Circuits Conference (ESSCIRC), Sep. 2021, Grenoble, France.  doi: https://doi.org/10.1109/ESSCIRC53450.2021.9567847

16. Y. Li, Y. Kim, E. Moon, J. Phillips, and I. Lee, "An Energy Autonomous Light Intensity Sensor for Monarch Butterfly Migration Tracking," IEEE European Solid-State Circuits Conference (ESSCIRC), Sep. 2021, Grenoble, France. doi: https://doi.org/10.1109/ESSCIRC53450.2021.9567888

17. Y. Li, Y. Wu, X. Zhang, E. Hamed, J. Hu, and I. Lee, "Developing a Miniature Energy-Harvesting-Powered Edge Device with Multi-Exit Neural Network," IEEE International Symposium on Circuit and Systems (ISCAS), May 2021, Daegu, South Korea. doi: https://doi.org/10.1109/ISCAS51556.2021.9401799

18. Y. Li and I. Lee, "An 111pW Voltage Reference with a Diode-Leakage-Decoupling Replica for High-Temperature Miniature IoT Systems," IEEE Custom Integrated Circuits Conference (CICC), Apr. 2021, Austin, TX, USA. doi: https://doi.org/10.1109/CICC51472.2021.9431577

19. M. Yang, R. Hsiao, G. Carichner, K. Ernst, J. Lim, D. A. Green II, I. Lee, D. Blaauw, and H.-S. Kim, “Migrating Monarch Butterfly Localization Using Multi-Modal Sensor Fusion Neural Networks,” IEEE European Signal Processing Conference (EUSIPCO), Jan. 2021, Amsterdam, Netherlands. doi: https://doi.org/10.23919/Eusipco47968.2020.9287842

20. J. Lim, E. Moon, M. Barrow, S. R. Nason, P. R. Patel, P. G. Patil, S. Oh, I. Lee, H.-S. Kim, D. Sylvester, D. Blaauw, C. A. Chestek, J. Phillips, and T. Jang, "A 0.19×0.17mm2 Wireless Neural Recording IC for Motor Prediction with Near-Infrared-Based Power and Data Telemetry," IEEE International Solid-State Circuits Conference (ISSCC), Feb. 2020, San Francisco, CA, USA. doi: https://doi.org/10.1109/ISSCC19947.2020.9063005

21. T. Kang, I. Lee, S. Oh, S, T. Jang, Y. Kim, H. Ahn, G. Kim, S.-U. Shin, S. Jeong, D. Sylvester, D. Blaauw, “A 1.7×4.1×2 mm3 Fully Integrated pH Sensor for Implantable Applications using Differential Sensing and Drift-Compensation,” IEEE Symposium on VLSI Circuits (SOVC), Jun. 2019, Kyoto, Japan. doi: https://doi.org/10.23919/VLSIC.2019.8778184

22. I. Lee, and D. Blaauw, “A 31 pW-to-113 nW Hybrid BJT and CMOS Voltage Reference with 3.6% 3 sigma inaccuracy from 0 oC to 170 oC for Low-Power High-Temperature Systems,” IEEE Symposium on VLSI Circuits (SOVC), Jun. 2019, Kyoto, Japan. doi: https://doi.org/10.23919/VLSIC.2019.8778113

23. I. Lee, E. Moon, Y. Kim, J. Phillips, and D. Blaauw, “A 10mm3 Light-Dose Sensing IoT2 System with 35-to-339nW 10-to-300klx Light-Dose-to-Digital Converter,” IEEE Symposium on VLSI Circuits (SOVC), Jun. 2019, Kyoto, Japan.  doi: https://doi.org/10.23919/VLSIC.2019.8778007

24. Y. Peng, D. Choo, S. Oh, I. Lee, T. Jang, Y. Kim. J. Lim, D. Sylvester, and D. Blaauw, “An Adiabatic Sense and Set Rectifier for Improved Maximum Power Point Tracking in Piezoelectric Harvesting with 541% Energy Extraction Gain,” IEEE International Solid-State Circuits Conference (ISSCC), Feb. 2019, San Francisco, CA, USA. doi: https://doi.org/10.1109/ISSCC.2019.8662341

25. I. Lee, G. Kim, E. Moon, S. Jeong, D. Kim, J. Phillips, and D. Blaauw, “A 179lux Energy-Autonomous Fully-Encapsulated 17mm3 Sensor Node with Initial Charge Delay Circuit for Battery Protection,” IEEE Symposium on VLSI Circuits (SOVC), Jun. 2018, Honolulu, HI, USA. doi: https://doi.org/10.1109/VLSIC.2018.8502287

26. X. Wu, I. Lee, Q. Dong, K. Yang, D. Kim, J. Wang, Y. Chen, Y. Zhang, M. Saligane, T. Ema, R. Nanjo, A. Harada, M. Yasuda, K. Kumeno, S. Miyoshi, M. Kawaminami, D. Sylvester, and D. Blaauw, “A 0.04mm3 16nW Wireless and Batteryless Sensor System with Integrated Cortex-M0+ Processor and Optical Communication for Intra-celluar Temperature Measurement,” IEEE Symposium on VLSI Circuits (SOVC), Jun. 2018, Honolulu, HI, USA. doi: https://doi.org/10.1109/VLSIC.2018.8502391

27. I. Lee, D. Sylvester, and D. Blaauw, “Subthreshold Voltage Reference With Nwell/Psub Diode Leakage Compensation for Low-Power High-Temperature Systems,” IEEE Asian Solid-State Circuits Conference (ASSCC), Nov. 2017, Seoul, South Korea. doi: https://doi.org/10.1109/ASSCC.2017.8240267

28. Q. Dong, I. Lee, K. Yang, D. Blaauw, and D. Sylvester, “A 1.02nW PMOS-only, Trim-Free Current Reference with 282ppm/oC from -40oC to 120oC and 1.6% within-Wafer Inaccuracy,” IEEE European Solid-State Circuits Conference (ESSCIRC), Sep. 2017, Leuven, Belgium. doi: https://doi.org/10.1109/ESSCIRC.2017.8094515

29. M. Cho, S. Oh, S. Jeong, Y. Zhang, I. Lee, Y. Kim, L.-X. Chuo, D. Kim, Q. Dong, Y.-P. Chen, M. Lim, M. Daneman, D. Blaauw, D. Sylvester, and H.-S. Kim, “A 6×5×4mm3 general purpose audio sensor node with a 4.7μW audio processing IC,” IEEE Symposium on VLSI Circuits (SOVC), Jun. 2017, Kyoto, Japan. doi: https://doi.org/10.23919/VLSIC.2017.8008521

30. Q. Dong, Y. Kim, I. Lee, M. Choi, Z. Li, J. Wang, K. Yang, Y-P. Chen, J. Dong, M. Cho, G. Kim, W-K. Chang, Y-S. Chen, Y-D. Chih, D. Blaauw, and D. Sylvester, “A 1Mb Embedded NOR Flash Memory with 39μW Program Power for mm-Scale High-Temperature Sensor Nodes,” IEEE International Solid-State Circuits Conference (ISSCC), Feb. 2017, San Francisco, CA, USA. doi: https://doi.org/10.1109/ISSCC.2017.7870329

31. X. Wu, Y. Shi, S. Jeloka, K. Yang, I. Lee, D. Sylvester, and D. Blaauw, “A 66pW discontinuous switch-capacitor energy harvester for self-sustaining sensor applications,” IEEE Symposium on VLSI Circuits (SOVC), June 2016, Honolulu, HI, USA. doi: https://doi.org/10.1109/VLSIC.2016.7573490

32. W. Lim, T. Jang, I. Lee, H.-S. Kim, D. Sylvester, and D. Blaauw, “A 380pW dual mode optical wake-up receiver with ambient noise cancellation,” IEEE Symposium on VLSI Circuits (SOVC), June 2016, Honolulu, HI, USA. doi: https://doi.org/10.1109/VLSIC.2016.7573481

33. T. Jang, M. Choi, Y. Shi, I. Lee, D. Sylvester, and D. Blaauw, “Millimeter-scale computing platform for next generation of Internet of Things,” IEEE Int. Conf. RFID, May. 2016, Orlando, FL, USA. doi: https://doi.org/10.1109/RFID.2016.7487997

34. I. Lee, W. Lim, A. Teran, J. Phillips, D. Sylvester, and D. Blaauw, “A >78%-Efficient Light harvester over 100-to-100klux with Reconfigurable PV-Cell Network and MPPT Circuit,” IEEE International Solid-State Circuits Conference (ISSCC), Feb. 2016, San Francisco, CA, USA. doi: https://doi.org/10.1109/ISSCC.2016.7418061

35. I. Lee, W. Jung, H. Ha, S. Jeong, Y. Kim, G. Kim, Z. Foo, J.-Y. Sim, D. Sylvester, and D. Blaauw, “An Ultra-Low-Power Biomedical Chip for Injectable Pressure Monitor,” IEEE Biomedical Circuits and Systems Conference (BIOCAS), Oct. 2015, Atlanta, GA, USA. doi: https://doi.org/10.1109/BioCAS.2015.7348313 (Invited)

36. S. Bang, J.-S. Seo, I. Lee, S. Jeong, N. Pinckney, D. Blaauw, D. Sylvester, and L. Chang, “A Fully-Integrated 40-Phase Flying-Capacitance-Dithered Switched-Capacitor Voltage Regulator with 6mV Output Ripple,” IEEE Symposium on VLSI Circuits (SOVC), June 2015. doi: https://doi.org/ 10.1109/VLSIC.2015.7231313

37. W. Lim, I. Lee, D. Sylvester, and D. Blaauw, “Batteryless Sub-nW Cortex-M0+ Processor with Dynamic Leakage-Suppression Logic,” IEEE International Solid-State Circuits Conference (ISSCC), Feb. 2015, Kyoto, Japan. doi: https://doi.org/10.1109/VLSIC.2015.7231313

38. M. Choi, I. Lee, T.-K. Jang, D. Blaauw, and D. Sylvester, “A 23pW 780ppm/°C Resistor-Less Current Reference Using Subthreshold MOSFETs,” IEEE European Solid-State Circuits Conference (ESSCIRC), Sep. 2014, Venice Lido, Italy. doi: https://doi.org/10.1109/ESSCIRC.2014.6942036

39. Y.-S. Kuo, P. Pannuto, G. Kim, Z. Foo, I. Lee, B. Kempke, P. Dutta, D. Blaauw, and Y. Lee, “MBus: A 17.5 pJ/bit/chip Portable Interconnect Bus for Millimeter-Scale Sensor Systems with 8 nW Standby Power,” IEEE Custom Integrated Circuits Conference (CICC), Sep. 2014, San Jose, CA, USA. doi: https://doi.org/10.1109/CICC.2014.6946046

40. S. Jeong, I. Lee, D. Blaauw, and D. Sylvester, “A 5.8nW, 45ppm/°C On-Chip CMOS Wake-up Timer Using a Constant Charge Subtraction Scheme” IEEE Custom Integrated Circuits Conference (CICC), Sep. 2014, San Jose, CA, USA. doi: https://doi.org/10.1109/CICC.2014.6946008

41. I. Lee, Y. Kim, S. Bang, G. Kim, H. Ha, Y.-P. Chen, D. Jeon, S. Jeong, W. Jung, M. Ghaed, Z. Foo, Y. Lee, J.-Y. Sim, D. Sylvester, and D. Blaauw, “Circuit Techniques for Miniaturized Biomedical Sensors,” IEEE Custom Integrated Circuits Conference (CICC), Sep. 2014, San Jose, CA, USA. doi: https://doi.org/10.1109/CICC.2014.6946070 (Invited)

42. I. Lee, Y. Lee, D. Sylvester, and D. Blaauw, “Low Power Battery Supervisory Circuit with Adaptive Battery Health Monitor,” IEEE Symposium on VLSI Circuits (SOVC), June 2014, Honolulu, HI, USA  doi: https://doi.org/10.1109/VLSIC.2014.6858363 (Selected as Symposium Technical Highlight)

43. D. Blaauw, D. Sylvester, P. Dutta, Y. Lee, I. Lee, S. Bang, Y. Kim, G. Kim, P. Pannuto, Y.-S Kuo, D. Yoon, W. Jung, Z. Foo, Y.-P. Chen, S. Oh, S. Jeong, M. Choi, “IoT Design Space Challenges: Circuits and Systems,” IEEE Symposium on VLSI Technology (SOVT), June 2014, Honolulu, HI, USA. doi: https://doi.org/10.1109/VLSIT.2014.6894411  (Invited)

44. G. Kim, Y. Lee, Z. Foo, P. Pannuto, Y.-S. Kuo, B. Kempke, M. Ghaed, S. Bang, I. Lee, Y. Kim, S. Jeong, P. Dutta, D. Sylvester, and D. Blaauw, “A Millimeter-Scale Wireless Imaging System with Continuous Motion Detection and Energy Harvesting,” IEEE Symposium on VLSI Circuits (SOVC), June 2014, Honolulu, HI, USA. doi: https://doi.org/10.1109/VLSIC.2014.6858425

45. G. Kim, A. Wolfe, R. Bell, S. Bang, Y. Lee, I. Lee, Y. Kim, L. Hsu, J. Kagan, M. Arias-Thode, B. Chadwick, D. Sylvester, and D. Blaauw, “Chip-On-Mud: Ultra-Low Power ARM-Based Oceanic Sensing System Powered by Small-Scale Benthic Microbial Fuel Cells,” IEEE International Symposium on Circuits and Systems (ISCAS), May 2014, Melbourne, VIC, Australia. doi: https://doi.org/10.1109/ISCAS.2014.6865552

46. Y. Kim, W. Jung, I. Lee, Q. Dong, M. Henry, M, D. Sylvester, and D. Blaauw, “27.8 A static contention-free single-phase-clocked 24T flip-flop in 45nm for low-power applications,” IEEE International Solid-State Circuits Conference (ISSCC), Feb. 2014, San Francisco, CA, USA. doi: https://doi.org/10.1109/ISSCC.2014.6757516

47. I. Lee, S. Bang, D. Yoon, M. Choi, S. Jeong, D. Sylvester, and D. Blaauw, “A Ripple Voltage Sensing MPPT Circuit for Ultra-Low Power Microsystems,” IEEE Symposium on VLSI Circuits (SOVC), June 2013, Kyoto, Japan.  doi: N/A (https://ieeexplore.ieee.org/abstract/document/6578673)

48. S. Bang, Y. Lee, I. Lee, Y. Kim, G. Kim, D. Blaauw, and D. Sylvester, "A fully integrated switched-capacitor based PMU with adaptive energy harvesting technique for ultra-low power sensing applications," IEEE International Symposium on Circuits and Systems (ISCAS), May 2013, Beijing, China. doi: https://doi.org/10.1109/ISCAS.2013.6571945

49. D. Jeon, Y. Kim, I. Lee, Z. Zhang, D. Blaauw, and D. Sylvester, “A 470mV 2.7mW Feature Extraction-Accelerator for Micro-Autonomous Vehicle Navigation in 28nm CMOS,” IEEE International Solid-State Circuits Conference (ISSCC), Feb. 2013, San Francisco, CA, USA. doi: https://doi.org/10.1109/ISSCC.2013.6487684

50. Z. Foo, D. Devescery, M. Ghaed, I. Lee, A. Madhavan, Y. Park, A. Rao, Z. Renner, N. Roberts, A. Schulman, V. Vinay, M. Wieckowski, D. Yoon, C. Schmidt, T. Schmid, P. Dutta, P. Chen, and D. Blaauw, “A Low-Cost Audio Computer for Information Dissemination among Illiterate People Groups,” IEEE Custom Integrated Circuits Conference (CICC), Sep. 2012, San Jose, CA, USA. doi: https://doi.org/10.1109/CICC.2012.6330652  

51. G. Kim, Y. Lee, S. Bang, I. Lee, Y. Kim, D. Sylvester, and D. Blaauw, “A 695pW Standby Power Optical Wake-up Receiver for Wireless Sensor Nodes,” IEEE Custom Integrated Circuits Conference (CICC), Sep. 2012, San Jose, CA, USA. doi: https://doi.org/10.1109/CICC.2012.6330652

52. I. Lee, S. Bang, Y. Lee, Y. Kim, G. Kim, D. Sylvester, and D. Blaauw, “A 635pW Battery Voltage Supervisory Circuit for Miniature Sensor Nodes,” IEEE Symposium on VLSI Circuits (SOVC), June 2012, Honolulu, HI, USA. doi: https://doi.org/10.1109/VLSIC.2012.6243860

53. Y. Lee, G. Kim, S. Bang, Y. Kim, I. Lee, P. Dutta, D. Sylvester, and D. Blaauw, “A Modular 1mm3 Die-stacked Sensing Platform with optical Communication and Multi-Modal Energy Harvesting,” IEEE International Solid-State Circuits Conference (ISSCC), Feb. 2012, San Francisco, CA, USA. doi: https://doi.org/10.1109/ISSCC.2012.6177065

54. Z. Foo, D. Devecsery, T. Schmid, N. Clark, R. Frank, M. Ghaed, Y. Kuo, I. Lee, Y. Park, Z. Renner, N. Slottow, V. Vinay, M. Wieckowski, D. Yoon, C. Schmidt, D. Blaauw, P. Chen, and P. Dutta, “A Case for Custom Silicon in Enabling Low-Cost Information Technology for Developing Regions,” ACM Symposium on Computing for Development, Dec. 2010, London, United Kingdom. doi: https://doi.org/10.1145/1926180.1926208

55. J. Cheon, I. Lee, J. Lee, Y. Chae, Y. Yoo, and G. Han, “An Analog Front-End of a Fire Detection SOC for a Fire Alarm System,” IEEE Sensors Conf., Oct, 2008, Lecce, Italy. doi: https://doi.org/10.1109/ICSENS.2008.4716555

56. Y. Chae, I. Lee, and G. Han, “A 0.7V 36μW 85dB-DR Audio ΔΣ Modulator Using Class-C Inverter,” IEEE International Solid-State Circuits Conference (ISSCC), Feb. 2008, San Francisco, CA, USA. doi: https://doi.org/10.1109/ISSCC.2008.4523271

57. I. Lee, Y. Chae, and G. Han, "A Low Power Dual-Mode Sigma-Delta Modulator for GSM/WCDMA Receivers," IEEE International Conference on Electronics, Circuits and Systems (ICECS), Dec. 2007, Marrakech, Morocco. doi: https://doi.org/10.1109/ICECS.2007.4511199 

Patents

1. D. Blaauw, D. Sylvester, M. Choi, I. Lee, and T. Jang, “Ultra low power temperature insensitive current source with line and load regulation,” U.S., grant (US 9,639,107 B2, May. 2, 2017)

2. I. Lee, Y. Lee, D. Sylvester, and D. Blaauw, “Electronic device with supervisor circuit for detecting resistance parameter of an energy storage device,” U.S., grant (US 9,429,627 B2, Aug. 30, 2016).

3. G. Han, Y. Chae, I. Lee, D. Lee, S. Lim, J. Cheon, “Switched capacitor circuit,” Korea, Registered (101087246, Nov. 21. 2011).

4. G. Han, I. Lee, Y. Chae “Inverter and inverter based system,” Korea, Registered (101069377, Sep. 26. 2011).

5. I. Lee, Y. Chae, G. Han, Korea, “Hysteretic analog to digital converter,” Korea, Registered (10093385, Dec. 15. 2009).

6. Y. Chae, I. Lee, G. Han, “Cardiac pacemaker and method of co-using amplifier using the same,” Korea, Registered (100933281, Dec. 14. 2009).

7. Y. Chae, I. Lee, M. Kwon, G. Han, “Time-interleaved sigma-delta modulator using single amplifier architecture,” Korea, Registered (100933280, Dec. 14. 2009).

8. Y. Chae, I. Lee, J. Choen, G. Han, S.Ham, “Decimation filter, analog to digital converter including the same, and image sensors including the converters,” U.S., Filed (20090295956)/ Korea, Disclosed (1020090123206, Dec. 2. 2009).

9. Y. Chae, I. Lee, G.Han, S. Ham, “Sigma-delta analog to digital converters and solid state image pickup device,” U.S., Registered (7,773,018, Aug. 10, 2010)/ Korea, Disclosed (1020090121952, Nov. 26. 2009).

10. Y. Chae, I. Lee, J. Choen, G. Han, S. Ham, “Apparatus and method for sigma-delta analog to digital conversion,” U.S., Registered ( 7,916,061, Mar. 29. 2011)/ Korea, Disclosed (1020090111012, Oct. 26. 2009).

Invited Talks

1. The 19th ROK-USA Forum on Nanotechnology, Gyeonggi-do, South Korea, Aug. 2025.

2. KETI, South Korea, Dec. 2024 & Mar. 2025. 

3. ETRI, South Korea, Dec. 2024. 

4. KERI, South Korea, Oct. 2024. 

5. IBS, South Korea, Oct. 2024.

6. Arizona State University, Tempe, AZ, Sep. 2024. 

7. The 18th ROK-USA Forum on Nanotechnology, Tempe, AZ, Sep. 2024.

8. PITT-NDETP Workshop, Pittsburgh, PA, July 2024.

9. National Pollinator Week, Pittsburgh, PA, Jun. 2024.

10. On-device AI Semiconductor Workshop, South Korea, Apr. 2024.

11. HSN, South Korea, Jan. 2024.

12. Qualitas Semiconductor, South Korea, Jan. 2024.

13. KIST, South Korea, Jan. 2024.

14. UC Davis, Davis, CA, May 2023.

15. IEEE Custom Integrated Circuits Conference (CICC) Forum, San Antonio, TX, Apr. 2023.

16. The 17th ROK-USA Forum on Nanotechnology, Seoul, South Korea, Apr. 2023.

17. MDPI 5th Electronics Webinar, Online, July 2022.

18. University of Delaware, Newark, DE, Oct, 2021.

19. University of Pittsburgh, Pittsburgh, PA, Feb. 2021.

20. University of Pittsburgh, Pittsburgh, PA, Sep. 2019.

21. North Carolina State University, Raleigh, NC, Mar. 2019.

22. Indiana University, Bloomington, IL, Mar. 2019.

23. University of Pittsburgh, Pittsburgh, PA, Jan. 2019.

24. IBM, Yorktown Heights, NY, Nov. 2018.

25. Samsung, Suwon, South Korea, May 2018.

26. Pennsylvania State University, University Park, PA, Mar. 2018.

27. Indiana University, Bloomington, IL, Mar. 2018.

28. International Symposium on Quality Electronic Design (isQED), Santa Clara, CA, Mar. 2016.