Hybrid Resonant Switched-Capacitor Converter for 48 V to 3.4 V Direct Conversion

As the power required by modern data center processors increases, the power architecture must be adapted; for example, 48 V distribution voltage allows to reduce copper losses by a factor 16 with respect to the use of traditional 12 V power architecture. In order to generate the required processor core voltage, a two-stage approach is usually preferred, where the intermediate bus voltage is generated using an unregulated resonant DC-DC converter as, for instance, an LLC converter. Compared to LLCs, hybrid resonant switched-capacitor converters (ReSCCs) make it possible to achieve large voltage conversion ratios without the need of high turns ratio transformers. In this paper, a novel hybrid ReSCC that performs a 48V-to-3.4 V direct conversion is presented. A prototype of the proposed converter has been implemented, capable of providing a continuous output power of 440 W with a maximum efficiency of 96.3% at 30 A load current.