A Novel Non-isolated GaN-based DC-DC Converter with High Step-Down Gain

With the emerging technology of wide-band-gap power semiconductors and modern ferrite materials, the switching frequency of dc-dc converters based on gallium nitride (GaN) devices can be further pushed to megahertz range and achieve higher power density. A high step-down gain, high efficiency non-isolated dc-dc converter is proposed for front-end dc-dc converters used in data centers. The proposed converter is composed of three active switches, two synchronous rectifiers, two clamping capacitors and two inductors. Compared with the conventional buck converters, the proposed converter has higher voltage gain and lower voltage stresses across the active switches. A 300W/1 MHz GaN-based experimental prototype is built and tested to verify the correctness and validity, demonstrating a peak efficiency of 93.3% and full-load efficiency of 90.7%.