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Technical Dialogue

Point-of-Load (POL) and Multi-Phase Converters

D05.8 - A 48-V-to-1-V Gallium Nitride Switching Bus Converter for Processor Vertical Power Delivery with 2.7 mm Thickness and 3048 W/in³ Power Density

Thursday, March 20, 2025
11:30 AM – 1:30 PM ET
Location: Level One, Hall A3
High-performance processors demand over 1000 A of current at a core voltage of 1 V or lower when running computationally intensive tasks, such as training artificial intelligence models, which necessitates the development of improved 48 V to point-of-load (PoL) power conversion solutions with higher efficiency and power density. In pursuit of improved performance for 48-V-to-PoL conversion, a switching bus converter (SBC) was recently proposed to achieve single-stage vertical power delivery and pushed the performance boundary of existing solutions. This work focuses on an ultra-low-profile, high-density implementation of the SBC, with high switching frequency enabled by Gallium Nitride field-effect transistors and an advanced packaging structure featuring recessed coupled inductors for vertical current flow. A 2.7 mm thick low-profile SBC hardware prototype was designed and built for 48-V-to-1-V conversion. The prototype was tested up to 405 A of output current at an output voltage of 1 V, achieving a high power density of 3048 W/in^3. At 0.8V and 420 A, it reached a power density of 2529 W/in^3, demonstrating promising performance compared to state-of-the-art solutions.