The use of different sources to energize a load is convenient in many applications, particularly those where two or more renewable energy sources are employed, such as energy harvesting, hybrid vehicles, and off‐grid systems. In these cases, a multi‐input converter is able to admit sources with different characteristics and, if necessary, select the output power of each source. Several to-pologies of multi‐input converters have been proposed to this aim; however, most of them are based on multistage designs, which decreases efficiency and increases control complexity, particularly when more than two sources are used. In this work, a three‐input step‐up converter, easy to control in open loop condition, is analyzed. A designed procedure is described, and experimental results are presented for a 1 kW power converter. The implemented converter results in a higher voltage gain and less storage element, keeping high efficiency compared to similar topologies. Using the procedure here proposed, this converter that was initially designed for photovoltaic applications is enabled to be used in medium‐ and high‐power applications, for example, when renewable energy sources are used.