The investigation provides the study of complex phenomenon in buck converters using Matlab and Simulink. To perform simulations different types of converter models are used: based on iterative maps, differential equations and real elements. The main objectives of this paper are to explore different types of complex behavior in the converters as system parameters are changed; compare simulation results and establish the possibilities of each model. Simulations are carried out using Matlab/Simulink environment that provides the wide range of elements for complete investigation procedure. Simulations as well as analytical results reveal that period doubling route to chaos is observed.