In one embodiment, a DC converter has a frequency adjusting device with a frequency selection circuit, a frequency change-over switch (17), a frequency generator (18), a threshold signal generator (19), a state machine (20) and a unit (21) for providing a ready signal (S3). The frequency selection circuit has an output (15), at which a control signal (S5) is provided, which is set up to select a frequency of the switching frequency signal (DCLK) of the DC converter. The invention further relates to a method for selecting a frequency of the DC converter.