An Improved Model to Calculate Inductance of Planar Air-Core Inductors

Abstract

To enhance the efficiency and power density of switched-mode power supplies, planar air-core magnetic components have gained more and more popularities. Without magnetic core to restrict flux, conventional reluctance model cannot be applied to solve inductance for planar air-core magnetic components. Based on uniform mesh and Neumann's formula, this paper proposes an analytical model to calculate inductance of planar air-core inductors. With simulation or measurement results as the benchmark, relative error of the proposed model is less than 10 ^% in wide dimension range. More importantly, compared with other existing models in literature, the proposed method has better accuracy and generality. The proposed model can be applied to solve inductance and do optimal design for planar air-core inductors.