Overview of High-Power Density Voltage Regulator Solutions for XPU Applications

As performance of XPUs (CPUs, GPUs, FPGAs, and other accelerators) enhances, their demanded power increases. This means higher current needs to be delivered with an increased number of phases for Voltage Regulator (VR) solutions. More VR phases occupy more board area which poses many challenges to board layout design, signal routing and performance (transient response and efficiency). In literature and industry, Vertical Power Delivery (VPD) is proposed as a potential solution, offering high-power density. This paper investigates the benefits and implementation challenges of high-power density solutions: PowerBlock and Elevated Inductor for multiphase VRs. Additionally, comparison analysis and experimental results of both solutions are presented.