This seminar discusses the challenges in achieving ultra-high efficiency, such as 99%, and ultra-high power density, such as 2kW/in3. Most of the seminar focuses on 48V to 12V converters although the concepts are broadly applicable for a wide range of voltage levels. After a review of the fundamental sources of losses in DC-DC converters and how to minimize them, the seminar provides in-depth evaluation on the most efficient and high density topologies presented in literature thus far. The key concepts for achieving higher than 99% efficiency at a power density of more than 2kW/in3 are: easily paralleled “modular” designs for lower conduction loss, multi-level structures for lower voltage stress, low switching frequency for lower switching losses, full duty ratio operation for maximum utilization of power switches, and new circuit topologies for significant reduction of the size for inductors. At the end, the seminar will propose and discuss a new power architecture for 48V to 0.7V (down to 0.3V), 2,000A (or higher), application that will achieve extremely high efficiency (40V-0.7V), extremely small size, and current sharing, expandable, fast dynamic response, etc.
