A 96.1% Efficiency 48V-to-IBV GaN Power Converter with Full-Wave Temperature-Compensated Current Sensing and Adaptive Slope Emulation Achieving 4.3% Full-Temperature Sensing Error for AI Data Center Applications

Data center becomes increasingly energy hungry which desperately requires highly efficient power conversion. Graphical processing units (GPUs) and high-bandwidth memory(HBM) demand a growing power for elevated computation, data communication and storage. Fig. 1. shows a data center vertical power delivery (VPD) architecture which consists of a multiphase 48V-to-intermediate-bus-voltage(IBV) converter in the first stage, as well as a multiphase intermediate-bus-voltage-to-0.8V step-down voltage regulators (VRs) in the second stage. A single-phase open-loop LLC converter is typically used in the intermediate-bus-voltage-to-12V IBC stage [1]; however, it demands a large PCB area for magnetic transformer and primary/secondary power devices. Instead, multiphase buck converters gain popularity due to smaller size of magnetic components, less power switches and maturity of control methods. Moreover, Gallium Nitride (GaN) devices, which shows a smaller parasitic capacitance and lower on-resistance in the same size compared to the silicon MOSFET counterpart, is an ideal power device used in data center to reduce power loss and solution size.