Single stage isolated 48V to 1.8V point of load converter utilizing an impedance control network for wide input range operation
This paper introduces a single stage isolated 48V to 1.8V point of load converter based on the impedance control network (ICN) resonant converter architecture. This point of load ICN converter achieves large step down while maintaining high efficiency across a wide range of input voltage and output power. Large step down is achieved through a combination of stacked inverters, a transformer and a resonant current doubler rectifier. High efficiency is achieved by utilizing the ICN architecture, which enables zero voltage and near zero current switching across wide operating ranges. The power density of the converter is enhanced by combining the three inductors of the ICN into a single integrated magnetic structure. A design methodology based on 3D finite element analysis is employed to optimize the magnetic components of the proposed ICN converter. A prototype 90 W ICN converter utilizing planar magnetics, designed to operate over an input voltage range of 36 V to 60 V and an output voltage of 1.8 V is built and tested. The prototyped converter achieves a peak efficiency of 88.7% and maintains efficiencies above 87.6% across its nearly 2:1 input voltage range, and above 86.6% across a 10:1 output power range.
2017 IEEE Energy Conversion Congress and Exposition (ECCE)