A Novel Non-isolated Bidirectional 48V-12V DCX Converter with Transformer-Coupled Gate Driver

In this paper, a novel non-isolated bidirectional DCX (NBDCX) converter is proposed. Compared with the conventional LLC-DCX converter, the NBDCX converter retains the original ZVS / ZCS soft-switching characteristics and has the advantages of smaller winding turns and higher efficiency, by connecting the primary and secondary sides of traditional LLC in series. Meanwhile, all switches in NBDCX converter have the same voltage and current stress, and the RMS currents in each winding of the transformer are also more balanced. Besides, a transformer-coupled gate driver is proposed for the NBDCX converter to reduce drive loss. Finally, the proposed converter is verified on a 150kHz NBDCX prototype with the highest efficiency of 96%.