In order to improve the efficiency of a driver circuit for controlling upper and lower switching means (T3, T4) for converting a direct voltage Ud into a clocked output voltage Ua for a resonant converter with a high-voltage section (HT) for controlling the upper switching means (T3) and a low-voltage section (NT) for controlling the lower switching means (T4), which switch the switching means (T3, T4) on alternately to one another, the switch-on phases of the switching means (T3, T4) being separated from one another by dead-time phases, there is provided a first circuit section which controls the duty cycle tein3 of the upper switching means (T3) as a function of the duty cycle tein4 of the lower switching means (T4), and receives control signals from the low-voltage section (NT) exclusively during the duty cycle tein4 of the lower switching means (T4).