Configurable Dual Output Non-Isolated Resonant Converter for 48 V Applications

Growth of electricity consumption for data center increases rapidly as computation continues to move into the cloud computing. Energy management has become a key issue for the next generation of data centers. 48 V step-down converters are often required in server, telecommunication and automotive applications. Using resonant topologies such as LLCs allows to obtain ZVS (Zero Volt Switch) turn-on for all the switches over the entire load range using magnetizing current, yielding high efficiency. Recently a non-isolated, fixed ratio DC-DC solution defined as switched tank converter was proposed for this application, followed by a different 48 V to 12 V implementation. In this paper a configurable, dual-output, non-isolated DC-DC resonant topology is investigated. A configuration yielding 10:1 and 5:1 output rails is explored in detail with two converter prototypes from the 48/54 V input bus, achieving high power density, high efficiency and a low profile. Experimental results for a very-low-profile 200+ W prototype module provide to show the effectiveness of the discussed system. More results, comprising a 500 W module, will be provided in the final paper.