Modelling and Control of a Novel High Step-down 48V-1V DC-DC Converter

This paper proposes a novel non-isolated buck- derived resonant DC-DC converter topology that achieves a significantly high step-down gain. Because of the limitations pertaining to the duty cycle limits and constraints related to minimum deadtime requirements that result in reduced efficiency and higher peak stress on power components, it is difficult to attain high step-down with a normal single switch buck converter. Multistage buck-derived topologies, including a greater number of active power devices, make the converter complex and inefficient in many cases. In this work, a novel circuit structure is proposed, that achieves a very high step-down gain without pushing duty cycles to the extreme limits, resulting in an efficient power conversion, making it very relevant to datacenters and point of load applications. To characterize the converter, state space averaging formulation is utilized, and corresponding gain plots have been presented. To examine the converter performance and closed loop performance, the converter is simulated for 200W load in MATLAB/Simulink, and it exhibits over 94% efficiency and 10ms settling time under 50% step change in load power. In addition to that, experimental results are also included for a laboratory proof-of-concept hardware prototype.