This paper presents a comprehensive analysis of two partial power structures: input parallel output series (IPOS) and input series output parallel (ISOP). By employing converter efficiency and power processing models, the most suitable partial power topology for different requirements can be determined. The analysis reveals that IPOS is better suited for step-up circuits, while ISOP excels in step-down applications. The findings are further validated through a prototype of a two-phase synchronous buck-boost converter, specifically designed to operate within a wide input voltage range of 38V to 72V DC, while delivering a fixed output voltage of 107V DC with a target power delivery of 1.2kW.
