Closed-loop model: An optimization of integrated thin-film magnetic devices

A generic analytical model has been developed to fully describe the flux closure through magnetic inductors. The model was applied to multiple device topologies including solenoidal single return path and dual return path inductors as well as spiral magnetic inductors for a variety of permeabilities and dimensions. The calculated inductance values from the analytical model were compared with simulated results for each of the analyzed device topologies and found to agree within 0.1 nH for the range of typical thin-film magnetic permeabilities (∼102 to 103). Furthermore, the model can be used to evaluate behavior in other integrated or discrete magnetic devices with either non-isotropic or isotropic permeability and used to produce more efficient device designs in the future.