A ballast (10) for powering at least one gas discharge lamp (20) comprises a switching converter (100) and an inverter (900). Switching converter (100) includes a transistor (130) and a control circuit (200) that provides substantially zero voltage switching of the transistor (130) at a very high frequency. Preferably, control circuit (200) includes a drive circuit (300), a turn-on synchronization circuit (400), a current mirror circuit (500), a rail voltage regulator circuit (600), and a lamp current regulator circuit (700). Drive circuit (300) is preferably realized by a circuit arrangement that includes a standard pulse-width modulation integrated circuit (310).