Title:  High Performance Embedded Inductors for High Conversion Ratio Integrated Voltage Regulators

Committee: 

Dr. Swaminathan, Advisor       

Dr. Raychowdhury, Chair

Dr. Mukhopadhyay

Abstract: The objective of the proposed research is to develop a high-performance embedded inductor for high conversion ratio 12V to 1V and 48V to 1V Package Integrated Voltage Regulator (PIVR) targeted for System on Chips (SoC) in data centers. Typical SoCs are powered with 1.7V, but with power consumptions rising over 100W the load current starts to go over 50A which becomes a problem. The trend for next-generation High Performance Computing (HPC) platforms is to supply the SoC directly with 12V or 48V. At these input voltages, the IVR is restricted to work below 5 MHz for high switching efficiency. However, at this frequency or below, the required inductance can be over 400 nH while the DC resistance must be below 20 mΩ. To address these properties, we have designed and demonstrated a novel embedded toroidal inductor technology, and we have optimized it to have 400 nH of inductance with 15 mOhm of DC resistance with a maximum inductance density of 125 nH/mm2 or 208 nH/mm3. This inductor can achieve over 95% of inductor efficiency from 2 MHz to 5 MHz, which in combination with Gallium-Nitride (GaN) MOSFET it can achieve 90% efficiency for 12V to 1V at 2 MHz and 2A of current.