In this paper electrical models of magneto-impedance (MI) sensors based on a continued fractions is introduced. The models can be easily applied to cylindrical and planar magnetic structures via the proper mapping of Bessel and coth functions to an approximated passive linear RL network, respectively. This is done representing those functions as continued fractions and identifying the topology and the passive lineal electrical elements as Cauer's type 2 networks. The equivalent circuits can be conveniently exploited for conditioning electronic purposes, or the characterization of the basis of the MI effect through the estimation of the sensor effective magnetic permeability. Simulation vs measurement results are presented to validate and demonstrate the scope of the model. © 2016 Elsevier B.V. All rights reserved.