An energy-saving circuit applies to a peripheral device for connection to a data bus of a host system. The energy-saving circuit includes a monitoring circuit for monitoring a communication via the data bus, a holding circuit for holding a connection state of the peripheral device, at least one switching element for interrupting a supply voltage for the peripheral device, and a control circuit. The control circuit is set up to recognize by means of the monitoring circuit the beginning of an idle state of the data bus, to hold the connection state of the peripheral device by activation of the holding circuit upon recognition of the idle state, and to interrupt the feeding of a supply voltage for the peripheral device by opening the at least one switching element.