Open-Source Multilevel Converter Power IC Design and Test

Open-source tools and PDKs facilitate the design, implementation and silicon validation of integrated circuits, circumventing the traditional barriers associated with this field. Power integrated circuits, conversely, are increasingly relevant in modern systems targeting energy-efficient applications. In this study, the design of a power integrated circuit is examined from the perspective of open-source silicon design, which has recently emerged as a feasible approach for acquiring functional silicon-proven designs with low entry barriers. Utilizing this workflow, we showcase the complete design, simulation, layout, and experimental validation of an integrated multilevel dc-dc converter: specifically, a three-level flying capacitor buck converter. Our system converts 3.3V dc bus levels to 1.8V and below, for a measured peak efficiency of 89.3%. The maximum measured load current is 250mA, using two conversion cores operating in interleaved mode. The system has been implemented in 6.27mm
²
of active area using the Skywater 130nm standard CMOS technology open-source PDK.