HIGH-VOLTAGE CHARGING CIRCUIT IN A VEHICLE, AND ON-BOARD VEHICLE ELECTRICAL SYSTEM

A vehicle-based high-voltage charging circuit is provided with an AC voltage terminal, at least two galvanically isolating DC-DC converters designed as step-up converters and a rectifier via which the DC-DC converters are connected to the AC voltage terminal, and a changeover switch. The charging circuit has a first and a second DC voltage terminal selectably connected to the first DC-DC converter via the changeover switch. The charging circuit has a third DC voltage terminal connected to the second DC-DC converter, wherein the charging circuit also has a controller which is set up, in a first mode, to drive the DC-DC converters according to a first target output voltage which is at least 750 V and at most 1000 V, and, in a second mode, to drive the DC-DC converters according to a second target output voltage which is at most 480 V or at most 450 V.