A joint collaboration between the University of Toronto and Sendyne Corp., New York, has yielded a new circuit that enables a smaller, lighter battery and power subsystem for tablet PCs and other portable devices.
The volume occupied by the power supply circuit has been a limiting factor for miniaturization of the electronics in mobile devices. Current power supply designs occupy anywhere between 20% and 80% of the volume of such devices, depending on the application. A significant portion of this volume is determined by the size of inductors and capacitors used in such power supply circuits.
To be presented at the IEEE Applied Power Electronics Conference (APEC) and Exhibition in Fort Worth TX on Thursday, March 20th, the circuit addresses these issues. This topology consumes less power than would normally be required to maintain stable dc bus voltage output of the battery subsystem in portable devices, and achieves a 9X reduction in size and cost of the output capacitor. As the trend in new device design is to utilize dual cell batteries for optimization of power delivery and cell life, the new architecture also provides for inexpensive, lossless balancing of the batteries in dual cell systems. Experimental results obtained from an 8-12V, 20W, 250KHz prototype demonstrate a peak efficiency of 93.4%.
The APEC presentation is entitled, “Assisting Converter Based Integrated Battery Management System for Low Power Applications.” Leading the project team is Professor Aleksandar Prodic, from the Electrical and Computer Engineering (ECE) Department of the University of Toronto. He is the founder of the Laboratory for Power Management and Integrated SMPS, where the development is taking place. Dr. Prodic, a recipient of several IEEE awards and distinctions, is an expert in power system design.