Models and tools for CMOS integrated inductors

In this paper we are reporting our research in the development of automatic tools to assist the designers in selecting and automatically laying-out integrated inductors. This task is accomplished by analyzing carefully the lumped equivalent circuit model for these passive components, and using different approaches and modifications depending on the required accuracy and application. As a result modified circuit models for integrated inductors based on the conventional lumped element model are proposed. Model development is based on measurements taken from more than 100 integrated spiral inductors designed and fabricated in a standard silicon process. We show the ability of the proposed models to accurately predict the integrated inductor behavior extending the frequency range where they can be applied as compared with the conventional model.