conducted at Ericsson AB and supervised by Martin Svensson
Examinator: Torbjörn Thiringer, Inst för elektroteknik
Opponent: Devgeet Kamleshkumar Patel
Most of the DC/DC converters operate with Silicon (Si) based MOSFET because of the matured technological advancements. Although it has the capability and the performance, new material like the Gallium Nitride MOSFET is offering better electrical performance in small package size. Hence, the Gallium Nitride (GaN) MOSFET is used in a DC/DC converter and its investigated.
The thesis focuses on the reduction in the module size with similar efficiency in comparison with the benchmarked Ericsson developed Silicon (Si) MOSFET based DC/DC converter. However, operating at the high switching frequency yields reduction in the overall converter module size. At the high frequency of 600kHz, the planar ER18 transformer is designed with 40% reduction in the core area. Furthermore, the overall design of the GaN MOSFET based half-bridge DC/DC converter yields 27.8% shrinkage in the total power-train area.
Also, the efficiency of the GaN MOSFET based DC/DC converter is studied. From the simulation model, an overall efficiency of 94% is observed. In the hardware testing, the benchmarked Si MOSFET based half-bridge DC/DC converter yielded a maximum efficiency of 94.6% and the GaN MOSFET based half-bridge DC/DC converter achieved a maximum efficiency of 93.6%.