A circuit arrangement is disclosed for ascertaining switching times for a DC-DC voltage converter which has an actuating unit, configured to actuate circuit breakers in a full bridge which are arranged on a high-voltage side of the DC-DC voltage converter. In addition, the circuit arrangement has at least one comparison unit which is configured to compare a first voltage U dropping across a circuit breaker arranged on a low-voltage side of the DC-DC voltage converter with a first predetermined reference voltage U. In addition, the circuit arrangement has a first measuring unit, configured to start a first time measurement when a pair of the circuit breakers in the full bridge is switched on by the actuating unit and to terminate the first time measurement when U>U. The first measuring unit is also configured to output an ascertained first measurement period for the first time measurement to the actuating unit, and the actuating unit is configured to actuate the circuit breakers on the basis of the ascertained first measurement period.