Professor Ka Nang Alex Leung

The great pleasure in life is doing what people say you cannot do

Profile Contacts Teaching Funded Educational Project Research Interests Research Group Publication Record Funded Research Projects
  1. Power Management for System-On-a-Chip Design in Nano-Scale Technology (RGC)
  2. A Power-Supply IC for WiMAX Transmitter (RGC)
  3. Transient-Enhanced Low-Dropout Regulators with Voltage-Spike Detector Based on Capacitive Coupling (RGC)
  4. Digital-Control SIMO DC-DC Converter with Enhanced Output Power of Individual Sub-Converter (RGC)
  5. Development of Fast Transient Low-Dropout Regulator Based on Dominant-Pole Tracking and Cancellation (RGC)
  6. Low-dropout Regulators with Multiple Pole-Zero Cancellations (RGC)
  7. Dual-Inductor Multiple-Output Buck-Boost DC-DC Converters with Enhanced Attenuation of Self- and Cross-regulations (RGC)
  8. Develop a Configurable RF Interface Module of UHF RFID Tag for Different Technology Nodes (ITF)
  9. Study the Design Challenges of 90nm Technology UHF RFID Tag IC (ITF)
  10. Power-Management Circuit for Passive UHF RFID Tag (ITF)
  11. High-Efficiency SIMO Power Converter for SoC (ITF)
  12. Development of Buck-Boost DC-DC Converter for USB Power Delivery 3.1 (ITF)
  13. Automated and Continuous Monitoring of Polycyclic Aromatic Hydrocarbon in Air Pollutants (ITF)
  14. Development of Capacitor-Free Three-Stage Amplifier Structure (Direct Grant)
  15. A Capacitor-less Low-Dropout Regulator with Supply Close to Threshold Voltage (Direct Grant)
  16. A Capacitor-less Low-Dropout Regulator with Digital-Assisted Transient Enhancer (Direct Grant)
Patents
  1. Frequency Compensation Techniques for Low-Power Multistage Amplifiers. U.S. Patent 6,208,206, Mar. 27, 2001, licensed.
  2. CMOS Voltage Reference. U.S. Patent 6,441,680, Aug. 27, 2002, licensed.
  3. Low Dropout Regulator Capable of On-Chip Implementation. U.S. Patent 7,205,827, Apr. 17, 2007, licensed.
  4. Single-Transistor-Control Low-Dropout Regulator. U.S. Patent 7,285,942, Oct. 23, 2007, licensed.
  5. Area-Efficient Capacitor-Free CMOS Low-Dropout Regulator. U.S. Patent 7,495,422, Feb. 24, 2009, licensed.
  6. End-Point Prediction Scheme for Voltage Regulators. U.S. Patent 7,619,395, Nov. 17, 2009, licensed.
  7. Low Dropout Regulator Capable of On-Chip Implementation. U.S. Patent RE42,116, Feb. 8, 2011.
  8. Single-Transistor-Control Low-Dropout Regulator. U.S. Patent RE42,335, May 10, 2011.
Representative Journal Publications
  1. K. N. Leung, P. K. T. Mok, W. H. Ki and J. K. O. Sin, "Three-Stage Large Capacitive Load Amplifier with Damping-Factor-Control Frequency Compensation," IEEE Journal of Solid-State Circuits, Vol. 35, No. 2, pp. 221-230, Feb. 2000.
  2. K. N. Leung and P. K. T. Mok, "Nested Miller Compensation in Low-Power CMOS Design," IEEE Transactions on Circuits and Systems II, Vol. 48, No. 4, pp. 388-394, Apr. 2001.
  3. K. N. Leung and P. K. T. Mok, "Analysis of Multi-Stage Amplifier - Frequency Compensation," IEEE Transactions on Circuits and Systems I, Vol. 48, No. 9, pp. 1041-1056, Sept. 2001.
  4. K. N. Leung and P. K. T. Mok, "A Sub-1-V 15-ppm/oC CMOS Bandgap Voltage Reference without Requiring Low Threshold Voltage Device," IEEE Journal of Solid-State Circuits, Vol. 37, No. 4, pp. 526-530, Apr. 2002.
  5. K. N. Leung and P. K. T. Mok, "A CMOS Voltage Reference Based on Weighted ΔVGS for CMOS Low-Dropout Linear Regulators," IEEE Journal of Solid-State Circuits, Vol. 38, No. 1, pp. 146-150, Jan. 2003.
  6. K. N. Leung, P. K. T. Mok and C. Y. Leung, "A 2-V 23-µA 5.3-ppm/oC Curvature-Compensated CMOS Bandgap Reference," IEEE Journal of Solid-State Circuits, Vol. 38, No. 3, pp. 561-564, Mar. 2003.
  7. K. N. Leung and P. K. T. Mok, "A Capacitor-Free CMOS Low-Dropout Regulator with Damping-Factor-Control Frequency Compensation," IEEE Journal of Solid-State Circuits, Vol. 38, No. 10, pp. 1691-1702, Oct. 2003.
  8. H. Lee, K. N. Leung and P. K. T. Mok, "A Dual-Path Bandwidth Extension Amplifier Topology with Dual-Loop Parallel Compensation," IEEE Journal of Solid-State Circuits, Vol. 38, No. 10, pp. 1739-1744, Oct. 2003.
  9. C. Y. Leung, P. K. T. Mok, K. N. Leung and M. Chan, "An Integrated CMOS Current-Sensing Circuit for Low-Voltage Current-Mode Buck Regulator," IEEE Transactions on Circuits and Systems II, Vol. 52, No. 7, pp. 394-397, Jul. 2005.
  10. H. Lee, P. K. T. Mok and K. N. Leung, "Design of Low-Power Analog Drivers Based on Slew-Rate Enhancement Circuits for CMOS Low-Dropout Regulators," IEEE Transactions on Circuits and Systems II, Vol. 52, No. 9, pp. 563-567, Sept. 2005.
  11. C. Y. Leung, P. K. T. Mok and K. N. Leung, "A 1-V Integrated Current-Mode Boost Converter in Standard 3.3/5-V CMOS Technologies," IEEE Journal of Solid-State Circuits, Vol. 40, No. 11, pp. 2265-2274, Nov. 2005.
  12. M. Siu, P. K. T. Mok, K. N. Leung, Y. H. Lam and W. H. Ki, "A Voltage-Mode PWM Buck Converter with End-Point Prediction," IEEE Transactions on Circuits and Systems II, Vol. 53, No. 4, pp. 294-298, Apr. 2006.
  13. S. K. Lau, P. K. T. Mok and K. N. Leung, "A Low-Dropout Regulator for SoC with Q-Reduction," IEEE Journal of Solid-State Circuits, Vol. 42, No. 3, pp. 658-664, Mar. 2007.
  14. T. Y. Man, K. N. Leung, C. Y. Leung, P. K. T. Mok and M. Chan, "Development of Single-Transistor-Control LDO Based on Flipped Voltage Follower for SoC," IEEE Transactions on Circuits and Systems I, Vol. 55, No. 5, pp. 1392-1401, Jun. 2008.
  15. S. K. Tang, K. P. Pun, C. S. Choy, C. F. Chan and K. N. Leung, "A Fully Differential Band-Selective Low Noise Amplifier for MB-OFDM UWB Receivers," IEEE Transactions on Circuits and Systems II, Vol. 55, No. 7, pp. 653-657, Jul. 2008.
  16. A. K. Y. Wong, K. P. Pun, Y. T. Zhang and K. N. Leung, "A Low-Power CMOS Front-End for Photoplethysmographic Signal Acquisition with Robust DC Photocurrent Rejection," IEEE Transactions on Biomedical Circuits and Systems, Vol. 2, No. 4, pp. 280-288, Dec. 2008.
  17. P. Y. Or and K. N. Leung, "An Output-Capacitorless Low-Dropout Regulator with Direct Voltage-Spike Detection," IEEE Journal of Solid-State Circuits, Vol. 45, No. 2, pp. 458-466, Feb. 2010.
  18. C. F. Chan, K. P. Pun, K. N. Leung, J. P. Guo, L. L. K. Leung and C. S. Choy, "Low-Power Continuously-Calibrated Clock Recovery Circuit for UHF RFID EPC Class-1 Generation-2 Transponders," IEEE Journal of Solid-State Circuits, Vol. 45, No. 3, pp. 587-599, Mar. 2010.
  19. A. K. Y. Wong, K. N. Leung, K. P. Pun and Y. T. Zhang, "A 0.5 Hz Highpass-Cutoff Dual-Loop Transimpedance Amplifier for Wearable NIR Sensing Device," IEEE Transactions on Circuits and Systems II, Vol. 57, No. 7, pp. 531-535, Jul. 2010.
  20. J. P. Guo and K. N. Leung, "A 6-µW Chip-Area-Efficient Output-Capacitorless LDO in 90-nm CMOS Technology," IEEE Journal of Solid-State Circuits, Vol. 45, No. 9, pp. 1896-1905, Sept. 2010.
  21. K. N. Leung and Y. S. Ng, "A CMOS Low Dropout Regulator with a Momentarily Current-Boosting Voltage Buffer," IEEE Transactions on Circuits and Systems I, Vol. 57, No. 9, pp. 2312-2319, Sept. 2010.
  22. P. Y. Or and K. N. Leung, "A Fast-Transient Low-Dropout Regulator with Load-Tracking Impedance Reduction and Loop-Gain Boosting," IEEE Transactions on Circuits and Systems II, Vol. 57, No. 10, pp. 757-761, Oct. 2010.
  23. M. Ho, K. N. Leung and K.-L. Mak, "A Low-Power Fast-Transient 90-nm Low-Dropout Regulator with Multiple Small-Gain Stages," IEEE Journal of Solid-State Circuits, Vol. 45, No. 11, pp. 2466-2475, Nov. 2010.
  24. K. N. Leung, Y. Y. Mai and P. K. T. Mok, "A Chip-Area Efficient Voltage Regulator for VLSI Systems," IEEE Transactions on VLSI Systems, Vol. 18, No. 12, pp. 1757-1762, Dec. 2010.
  25. M. Ho and K. N. Leung, "Dynamic Bias-Current Boosting Technique for Ultra-Low-Power Low-Dropout Regulator in Biomedical Applications," IEEE Transactions on Circuits and Systems II, Vol. 58, No. 3, pp. 174-178, Mar. 2011.
  26. J. B. Jia and K. N. Leung, "A Digital-Control Single-Inductor Triple-Output DC-DC Converter with Pre-Sub-Period Inductor-Current Control," IEEE Transactions on Power Electronics, Vol. 27, No. 4, pp. 2028-2042, Apr. 2012.
  27. Y. Q. Zheng, H. Chen and K. N. Leung, "A Fast-Response Pseudo-PWM Buck Converter with PLL-Based Hysteresis Control," IEEE Transactions on VLSI Systems, Vol. 20, No. 7, pp. 1167-1174, Jul. 2012.
  28. K. W. Li, K. N. Leung and L. L. K. Leung, "Sub-mW LC Dual-Input Injection-Locked Oscillator for Autonomous WBSNs," IEEE Transactions on VLSI Systems, Vol. 21, No. 3, pp. 546-553, Mar. 2013.
  29. T. W. Mui, M. Ho, K. H. Mak, J. P. Guo, H. Chen and K. N. Leung, "An Area-Efficient 96.5%-Peak-Efficiency Cross-Coupled Voltage Doubler with Minimum Supply of 0.8V," IEEE Transactions on Circuits and Systems II, Vol. 61, No. 9, pp. 656-660, Sep. 2014.
  30. K. H. Mak and K. N. Leung, "A Signal- and Transient-Current Boosting Amplifier for Large Capacitive Load Applications," IEEE Transactions on Circuits and Systems I, Vol. 61, No. 10, pp. 2777-2785, Oct. 2014.
  31. K. H. Mak, M. W. Lau, J. P. Guo, T. W. Mui, M. Ho, W. L. Goh and K. N. Leung, "A 0.7-V 24-µA Hybrid OTA Driving 15-nF Capacitive Load with 1.46-MHz GBW," IEEE Journal of Solid-State Circuits, Vol. 50, No. 11, pp. 2750-2757, Nov. 2015.
  32. H. Wang, X. Tang, C. S. Choy, K. N. Leung and K. P. Pun, "A 5.4-mW 180-cm Transmission Distance 2.5-Mbps Advanced Techniques Based Novel Intra-Body Communication Receiver Analog Front End," IEEE Transactions on VLSI Systems, Vol. 23, No. 12, pp. 2829-2841, Dec. 2015.
  33. Y. Q. Zheng, M. Ho, J. P. Guo, K.-L. Mak and K. N. Leung, "A Single-Inductor Multiple-Output Auto-Buck-Boost DC-DC Converter with Auto Phase Allocation," IEEE Transactions on Power Electronics, Vol. 31, No. 3, pp. 2296-2313, Mar. 2016.
  34. M. Ho, J. P. Guo, T. W. Mui, K. H. Mak, W. L. Goh, H. C. Poon, S. Bu, M. W. Lau and K. N. Leung, "A Two-Stage Large-Capacitive-Load Amplifier with Multiple Cross-Coupled Small-Gain Stages," IEEE Transactions on VLSI Systems, Vol. 24, No. 7, pp. 2580-2592, Jul. 2016.
  35. M. Ho, J. P. Guo, K. H. Mak, W. L. Goh, S. Bu, Y. Q. Zheng, X. Tang and K. N. Leung, "A CMOS Low-Dropout Regulator with Dominant-Pole Substitution," IEEE Transactions on Power Electronics, Vol. 31, No. 9, pp. 6362-6371, Sep. 2016.
  36. Y. Q. Zheng, M. Ho, J. P. Guo and K. N. Leung, "A Single-Inductor Multiple-Output Auto-Buck-Boost DC-DC Converter with Tail Current Control," IEEE Transactions on Power Electronics, Vol. 31, No. 11, pp. 7857-7875, Nov. 2016.
  37. S. Bu, J. P. Guo and K. N. Leung, "A 200-ps-Response-Time Output-Capacitorless Low-Dropout Regulator with Unity-Gain Bandwidth >100 MHz in 130-nm CMOS," IEEE Transactions on Power Electronics, Vol. 33, No. 4, pp. 3232-3246, Apr. 2018.
  38. S. Bu, K. N. Leung, Y. Lu, J. P. Guo and Y. Q. Zheng, "A Fully Integrated Low-Dropout Regulator with Differentiator-Based Active Zero Compensation," IEEE Transactions on Circuits and Systems I, Vol. 65, No. 10, pp. 3578-3591, Oct. 2018.
  39. C. H. Hung, Y. Q. Zheng, J. P. Guo and K. N. Leung, "Bandwidth and Slew Rate Enhanced OTA with Sustainable Dynamic Bias," IEEE Transactions on Circuits and Systems II, Vol. 67, No. 4, pp. 635-639, Apr. 2020.
  40. X. Ding, P. K. Chan and K. N. Leung, "A 40nm CMOS Hysteretic Buck DC-DC Converter with Digital-Controlled Power-Driving-Tracked-Duration Current Pump," IEEE Access, Vol. 8, pp. 177374-177384, Sep. 2020.
  41. Y. Q. Zheng, J. P. Guo and K. N. Leung, "A Single-Inductor Multiple-Output Buck/Boost DC-DC Converter with Duty-Cycle and Control-Current Predictor," IEEE Transactions on Power Electronics, Vol. 35, No. 11, pp. 12022-12039, Nov. 2020.
  42. Y. H. Woo, J. X. Yang, J. P. Guo, Y. Q. Zheng and K. N. Leung, "A Hybrid Low-Dropout Regulator with Load Regulation Correction," IEEE Access, Vol. 10, pp. 25106-25113, 2022.
  43. Y. H. Woo, J. X. Yang, J. W. Li, J. P. Guo, Y. Q. Zheng and K. N. Leung, "An Analog-Assisted Digital LDO With Dynamic-Biasing Asynchronous Comparator," IEEE Access, Vol. 10, pp. 56996-57002, 2022.
  44. Y. Zhou, Q. Q. Cheng, J. W. Li, Y. Q. Zheng and K. N. Leung, "Full-Wave Sense-FET-Based Inductor-Current Sensor with Wide Dynamic Range for Buck Converters," IEEE Transactions on Circuits and Systems II, Vol. 69, No. 4, pp. 2041-2045, Apr. 2022.
  45. J. X. Yang, B. Li, K. N. Leung, Z. J. Chen and Y. Q. Zheng, “A Triple-Mode DC-DC Converter with Wide Input and Load Ranges for Energy Harvesting in IoT Edge Nodes,” IEEE Transactions on Circuits and Systems II, Vol. 69, No. 12, pp. 4694-4698, Dec. 2022.
  46. Y. Zhou, J. W. Li, X. Liu, Y. Q. Zheng and K. N. Leung, “Bidirectional Buck-Boost Converter with Reduced Power Loss and No Right-Half-Plane Zero,” IEEE Transactions on Power Electronics, Vol. 38, No. 2, pp. 2127-2042, Feb. 2023.
  47. C. Gao, S. He, P. Davari, K. N. Leung, P. C. Loh and F. Balaabjerg, "Passivity-Based Design of Resonant Current Controllers without Involving Partial Derivative," IEEE Transactions on Power Electronics, Vol. 38, No. 12, pp. 15102-15108, Dec. 2023.
  48. C. Gao, S. He, B. Cui, B. Zhang, K. N. Leung and P. C. Loh, "Quantization Effects on Digital-PR-Controlled Active Power Filter," IEEE Journal of Emerging and Selected Topics in Power Electronics, Vol. 11, No. 6, pp. 5785-5797, Dec. 2023.
  49. Y. Zhou, H. T. Wang, Y. L. Xiong, X. Liu, Y. Q. Zheng, K. P. Pun and K. N. Leung, "A Direct 24V-to-1V Multi-Level Multi-Phase Hybrid Buck Converter with Automatic VCF Balancing and Current Sharing Mechanism," IEEE Journal of Emerging and Selected Topics in Power Electronics, Vol. 11, No. 6, pp. 5954-5968, Dec. 2023.
  50. Y. J. Lin, X. Liu and K. N. Leung, "A Bandwidth-Boosted Hybrid LDO with Spike-To-Time Converter for Near-Threshold Regulation," IEEE Transactions on Power Electronics, Vol. 39, No. 3, pp. 3452-3463, Mar. 2024.
  51. J. M. Li, X. Liu and K. N. Leung, “A 24-to-240W 95.6%-Efficiency <300-µs-Settling-Time Hybrid MCR/PT Wireless Power Transfer System,” IEEE Transactions on Power Electronics, Vol. 39, No. 7, pp. 8928-8946, Jul. 2024.
  52. J. Y. Ruan, J. M. Jiang, C. Z. Ding, Y. X. Li, Y. H. Wu, K. N. Leung and X. Liu, "A 2.8 µs Response Time 95.1% Efficiency Hybrid Boost Converter with RHP Zero Elimination for Fast-Transient Applications," IEEE Journal of Solid-State Circuits, accepted.
Representative Conference Publications
  1. K. N. Leung, P. K. T. Mok, W. H. Ki and J. K. O. Sin, "Damping-Factor-Control Frequency Compensation Technique for Low-Voltage Low-Power Large Capacitive Load Applications," IEEE International Solid-State Circuits Conference (ISSCC), San Francisco, California, USA, pp. 158-159, Feb. 1999.
  2. K. N. Leung and P. K. T. Mok, "A CMOS Voltage Reference Based on Weighted Difference of Gate-Source Voltages between PMOS and NMOS Transistors for Low Dropout Regulator," The 27th European Solid-State Circuits Conference (ESSCIRC), Villach, Austria, pp. 88-91, Sept. 2001.
  3. K. N. Leung, P. K. T. Mok and C. Y. Leung, "A 2-V 23-µA 5.3-ppm/oC 4th-Order Curvature-Compensated CMOS Bandgap Reference," IEEE Custom Integrated Circuits Conference (CICC), Orlando, Florida, USA, pp. 457-460, May 2002.
  4. P. K. T. Mok and K. N. Leung, "Design Considerations of Recent Advanced Low-Voltage Low-Temperature-Coefficient CMOS Bandgap Voltage Reference," IEEE Custom Integrated Circuits Conference (CICC), Orlando, Florida, USA, pp. 635-642, Oct. 2004.
  5. J. P. Guo and K. N. Leung, "A 25mA CMOS LDO with −85dB PSRR at 2.5MHz," IEEE Asian Solid-State Circuits Conference (ASSCC), Singapore, pp. 381-384, Nov. 2013.
  6. J. Ruan, J. M. Jiang, C. Z. Ding, K. Yuan, K. N. Leung and X. Liu, "A Li-ion-Battery-Input 1-6-V Output Bootstrap-Free Hybrid Buck-or-Boost Converter without RHP Zero Achieving 97.3% Peak Efficiency 6μs Recovery Time and 1.13µs/V DVS Rate," IEEE International Solid-State Circuits Conference (ISSCC), San Francisco, California, USA, pp. 148-149, Feb. 2024.