Step-up driver with minimal switching frequency

The invention relates to an electronic ballast comprising a step-up converter for operating a discharge lamp. The electronic ballast is embodied in such a way as to disconnect a switching element (T) in the step-up converter when a maximum current value of the current flowing through the switching element is reached. The electronic ballast comprises a holding circuit (HS) which is provided with a time-function element (R, C) and is embodied in such a way that it sets the time-function element (R, C) when the switching element (TI) is disconnected and reconnects the switching element after a time interval defined by the time-function element (R, C).