This paper deals with a global study of numerical control implementation applied to a DC-DC buck converter with two techniques, classical control technique (PI control) and robust control technique (H-infinity loop-shaping control). The H-infinity loop-shaping control is applied to improve the performance and the stability robustness of this power converter based on pulse-width-modulation (PWM) techniques. The experimental results are very promising. They show that Hinfinity loop-shaping control performs better than PI control. Hinfinity loop-shaping control reject disturbance and noise produce by the DC-DC power converter. In addition to experimental validation, the other added value of this paper is to demonstrate the feasibility of easily implementing robust numerical controls allowing rejecting disturbances without real impact on computing time, which is very important for embedded power converter applications.