This paper proposes to use a white-box approach to identify the parameters of an electronic DC-DC buck converter. It discretizes the differential equations governing the dynamic of such system, which are used to identify the parameters of the electronic components of the converter and the control loop. The proposed method is used to calculate the system parameters from the open loop and closed loop outputs, that is, the steady state and transient state stages of the output signals. The approach is validated by comparing simulation results from PSIM models of the converter with experimental data obtained from a commercial non-synchronous buck converter. Both simulation and experimental results show the feasibility and accuracy of the proposed approach in identifying the parameters of the converter, thus being feasible to obtain a full representation of such power converter. I.