Multiphysics Challenges and Opportunities for Integrated Voltage Regulators in Power Delivery Architectures

Integrated voltage regulator (IVR)-based power delivery architectures have become a growing trend in high-performance computing (HPC) systems. Integrated power delivery architectures typically feature high-frequency switching devices and embedded passive components, which can be integrated either inside the die or in the package. However, dense functional integration in such architectures though necessary brings a new set of challenges to system designers. In this article, we study the impact of heterogeneous integration on the design of power delivery architectures that addresses issues related to electrical, thermal, and electromagnetic domains through test cases. The key design problems arising out of heterogeneous integration and the solutions for each of the domains are identified. Although the electrical impedance profile seen by the load becomes flatter in the frequency domain with fewer resonances, noise coupling at the load increases due to the close proximity of noise sources. The electromagnetic interference (EMI) levels are higher, and therefore, more EMI and noise mitigating filters are needed for judicious placement at the package and die level. High thermal resistance associated with embedded passives results in a threshold for power losses in embedded inductors beyond which the conventional top-level cooling is insufficient and a local cooling solution is needed.