A DC /
DC converter (1) having a plurality n of two-pole inverters (2a, 2b) connected in parallel or in series, n transformers (Ta, Tb) and n two-pole rectifiers (3a, 3b) connected in parallel or in series is described. One
inverter (2a, 2b) each and one
rectifier (3a, 3b) each are connected to a
transformer (Ta, Tb). The inverters (2a, 2b, 2a′, 2b′) are in turn connected to a control which is provided for frequency-synchronous actuation of the inverters (2a, 2b, 2a′, 2b′) with a 180° / n phase shift. According to the invention, leakage inductances (LS1, LS2) of the transformers (Ta, Tb, Ta′, Tb′), together with capacitors (C1, C2) of the inverters (2a, 2b , 2a′, 2b′) and / or capacitors (C3, C4) of the rectifiers (3a, 3b, 3a′, 3b′), form in each case a resonating circuit whose resonant frequency is substantially twice as great as a
clock frequency of the
control signal. Furthermore, an AC /
DC converter (6) is described which has a DC /
DC converter (1) according to the invention with an AC / DC stage (5) connected on the input side.