Space on a server board is extremely precious, and servers – especially those designed for performing high-end computation functions such as Artificial Intelligence (AI) – are demanding more and more power. Simultaneously, GPUs are becoming quite common in AI systems. These GPUs are putting additional demands on power conversion requirements, where voltages as low as 0.6 V are required under certain operating conditions. Requirements now routinely top 3 kW per board with several systems requiring as much as 5 kW.
These stringent power requirements have necessitated changes in basic power conversion architecture. Many server designs are switching from rack-based 48 V isolated, regulated DC-DC converters that convert to 12 V, to non-isolated, unregulated 48 V DC-DC converters mounted on the server boards. With board space at a premium, high power density architectures become the holy grail for power systems.