A vehicle-side charging circuit includes an AC-voltage interface, a rectifier connected thereto and at least one first and one second DC-to-DC converter. The DC-to-DC converters are electrically isolating, and each have at least one intermediate circuit capacitor and at least one switch unit. The charging circuit also includes an on-board electrical system connection. The rectifier is connected to the on-board electrical system connection by way of the DC-to-DC converters. The charging circuit has a switch device which connects the DC-to-DC converters so as to be switchable between one another. In a first switching state, the switching device connects the two intermediate circuit capacitors and the switching units of the DC-to-DC converters in parallel and, in a second switching state, connects the intermediate circuit capacitors and the switch units in series.