Design Equations for Spiral and Scalable Cross Inductors on 0.35 μm CMOS Technology

This paper presents a set of design equations for spiral and new scalable cross inductors in CMOS 0.35 μm technology, relating electrical parameters of the inductor's equivalent circuit as functions of its geometric dimensions. The procedure used to derive the design equations is described and involves electromagnetic simulation of inductors with different geometric dimensions, extraction of values for equivalent circuit model elements for each inductor and the use of multivariate regression analysis applied to generalized linear models (GLM) based on Design of Experiments (DoE). A nine element π-type equivalent electrical circuit was used for the inductors, where all element values are constants, allowing simulation on SPICE-like software. Results from the models obtained for both spiral and scalable cross inductors presented closely match to the simulated results.