This paper presents a comprehensive small-signal MATLAB/Simulink model for the DC-DC buck converter operated under Continuous Conduction Mode (CCM). Initially, the buck converter is modeled using state-space average model and dynamic equations,depicting the converter, are derived. Then, a detailed MATLAB/Simulink model utilizing SimElectronics Toolbox is developed. Finally, the robustness of the converter model is verified against input voltage variations and step load changes. Simulation results of the proposed model, show that the output voltage and inductor current can return to steady state even when it is influenced by load and/orinput voltage variation, with a very small overshoot and settling time. The proposed model can be used to design powerful, precise and robust closed loop controller that can satisfy stability and performance conditions of the DC-DC buck regulator. This model can be used in any DC-DC converter (Buck, Boost, and Buck-Boost) by modifying the converter mathematical equations.

Index Terms - Small-signal model; State-space averaging; Buck converter; MATLAB/Smulink