Impedance measurements are widely used to characterize the behavior of n-windings magnetic components. The identification process is realized manually and becomes more and more difficult as the number of equivalent circuit parameters increases. This paper deals with an automatic identification method based on Rational Function Approximation (RFA) which enables to obtain these parameter values very quickly and leads to reliable models. The effectiveness of such method is demonstrated with the characterization of a planar common mode inductor and a toroidal coupled inductor. © 2011 IEEE.