A power supply system has an inductive device, a plurality of switching devices for providing connection of the inductive device to input and output nodes and a ground node, and a switch driver circuit for driving the switching devices so as to enable the power supply to operate in a boost mode to increase the input voltage, in a buck mode to decrease the input voltage, and in a solid-state flyback mode to transfer between the boost mode and the buck mode. In the solid-state flyback mode, the switching devices are controlled to provide switching of the inductive device between an input state in which the inductive device is connected between the input node and the ground node, and an output state in which the inductive device is connected between the ground node and the output node.