April 30, 2010
Speaker: Dr. Hoi Lee, University of Texas at Dallas
This talk describes analog circuit techniques to improve performances of a wireless power transmission system in cochlear implants and a portable power management system in handheld electronic devices. In the wireless power transmission system, high system power efficiency is crucial not only to prolong the battery runtime but also to minimize the potential tissue damage caused by overheating. New circuit architectures/techniques in both the integrated CMOS rectifier and the switched-capacitor charge pump that are embedded inside the body will be addressed to improve the system power efficiency. In portable power management applications, both switched-mode DC/DC converters (SMPC) and low-dropout regulators (LDO) are fundamental power modules. This talk will also discuss using dynamically-biased shunt feedback to improve transient response of the LDO and to enable SMPC to operate at high switching frequencies through increasing the current-sensing speed under low power condition.
Dr. Hoi Lee received the B.Eng., M.Phil., and Ph.D. degrees in electrical and electronic engineering from the Hong Kong University of Science and Technology in 1998, 2000, and 2004, respectively. In January 2005, he joined the Department of Electrical Engineering, University of Texas at Dallas, where he is an Assistant Professor. His current research interests include power management integrated circuits for portable, energy harvesting, solid-state lighting, and biomedical applications, integrated bioelectronics for cochlear and neural prosthesis, and low-voltage low-power analog and mixed-signal circuit techniques. Dr. Lee was the recipient of the Best Student Paper Award at the 2002 IEEE Custom Integrated Circuits Conference. He has served as an Associate Editor of the IEEE Transactions on Circuits and Systems-II from 2007 to 2009. He is currently on the Technical Program Committee of the IEEE Custom Integrated Circuits Conference, and the Analog Signal Processing and the Power Systems and Power Electronic Circuits Technical Committees of the IEEE Circuits and Systems Society