A peripheral device has a bus-controlled switching arrangement for operating a power supply. A device comprises a bus interface adapted for communicating with a remote device via a bus. A switch circuit is connected between the bus interface and a power supply. The switch circuit is operative, when the power supply is in an inactive state, for sensing bus activity and for generating a signal for activating the power supply in response to the sensed bus activity, wherein the switch circuit has no power dissipation when no activity is sensed on the bus.