A power supply with non-isolated DC DC splitting includes n conversion cells that are interlaced. The splitting switch of each cell is placed in a resonant circuit. The resonant circuit makes it possible to obtain a switching to the open state of said switch at zero current and voltage. The ripple at the input and output is minimized and the efficiency improved. In particular, the wiring inductances in the charge transfer loop of each cell no longer have negative effects on the efficiency. The cell may be of boost, buck, buck/boost, Cuk or SEPIC topology.