Ćuk converter

Electrical engineering

Physics

Engineering

Inductor

Buck converter

Composite material

Power (physics)

Voltage

Topology (electrical circuits)

Materials science

Power density

Electronic engineering

Converters

Gallium nitride

Layer (electronics)

Buck–boost converter

Forward converter

Quantum mechanics

Transformer

Boost converter

IEEE Transactions on Industrial Electronics

A high-efficiency, high-power-density Sigma converter for a 48 V rack architecture in data centers is proposed in this paper. The Sigma converter is a quasi-parallel converter that uses a high-efficiency unregulated converter to deliver the bulk power to the load. A small buck converter is responsible for regulating the output voltage with prescribed dynamic responses. A design guideline for Sigma converter with integrated magnetics is provided in this paper. The unregulated converter is an LLC converter designed with a printed circuit board (PCB) winding matrix transformer, a structure which integrates four elemental transformers into one core. The buck converter is designed with discrete gallium nitride (GaN) devices and a PCB winding inductor. The proposed Sigma converter operates at 48 V input and 1 V-80 A output and can achieve a power density of 420 W/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> as well as a peak efficiency of 94%.

Single-Stage High-Efficiency 48/1 V Sigma Converter With Integrated Magnetics