Novel automated simulator-independent ESD model characterization method based on Differential evolution and Nelder-Mead Simplex algorithms is presented in this paper. It offers an alternative for time and humanresources demanding manual characterization that is still widely used. The paper also presents stable macro-models of the four most often used snapback-based protection devices in CMOS technologies, i.e., NMOST and three variants of silicon-controlled rectifier structure. These macro-models were used for evaluation of the proposed method and the results are included and discussed.