This work addresses the 48 V to 12 V regulated conversion with a high-power density converter, which maintains a high efficiency thanks to a non-isolated sigma connection (or ISOP, Input-Series Output-Parallel connection). As a result, most of the power flows through a high-efficiency, autotransformer-based resonant and soft-switched converter, while regulation is achieved with a fraction of the processed power through a boost converter. This paper shows results for a 1.2 kW solution in a 25x51 mm area, with a power density exceeding 1kW/in3.
