The advances in artificial intelligence (AI) and machine learning (ML) are resulting in the emergence of a new generation of ultra-powerful graphical processing units (GPUs). The latest datacenter-grade GPU cards are overwhelmed with power delivery circuits using the traditional two-stage 12V intermediate bus voltage (IBV). The next-generation GPU is expected to double in power and package size, leaving even tighter space for power delivery. This work focuses on the vertical power delivery solution using a two-stage conversion with a 1.8V IBV. Stage 1 is a dc transformer that steps down 48 V to 1.8 V and stage 2 is a 1.8 V/0.8 V packaged voltage regulator VR prepared to be stacked vertically underneath the GPU. This work is focused on the design of stage 1 that uses an LLC resonant circuit featuring soft-switching, hence resulting in high frequency and high-power density. The converter is designed with a novel array of 14 transformers (60 A each) distributed along the GPU package edge to minimize the power distribution network (PDN) losses at 1.8 V. The converter can achieve an efficiency of up to 95.2% and a power density of 2400 W/in3.
.jpg "Pranav Raj Prakash, MS photo")