A power supply device and method for a household appliance is disclosed. The power supply device comprises a switching converter having a rectifying stage, electrically connected with the mains, a bus capacitor, electrically connected in parallel with at least one output terminal of the rectifying stage, a first and second resonant tank, electrically connected with at least a terminal of the bus capacitor, a first and second switching device respectively having a first and second switching period and are connected respectively with the first and second resonant tank. The power supply device further comprises a control means for controlling the first and second switching device. The control means operates at least one of a first switching device independently from the operating conditions of a second switching device. The control means operates the second switching device depending on the operating conditions of the first switching device.