This paper shows the analysis and implementation of a hybrid DC–DC power converter. The proposed topology consists of a series linear voltage regulator in parallel with a switching step-down converter. This topology can provide small ripple at the output voltage, fast responses for load variations and high efficiency for high load current conditions. In the hybrid structures there is not a classical feedback loop as in DC-DC converters, but they are feedback systems too. Therefore, their smallsignal analysis is important to assure stability of the implemented power supply system. From the analysis proposed we deduce the critical components that induce instability to the converter and how to improve the final design.