Abstract: The present invention relates to a driver circuit for an HID lamp having a circuit arrangement for applying a radiofrequency signal for the purpose of starting the lamp and for applying a low-frequency signal for the purpose of operating the lamp after starting, the driver circuit being designed to drive the HID lamp, immediately after starting, using a radiofrequency signal for a period of time, the period of time being variable and depending on at least one operating parameter for the lamp which is set after starting. It also relates to a corresponding method for operating an HID lamp.