Disclosed is an electronic device comprising an inductive element configured to function in a communication mode as an antenna for picking up communication signals, and in a power conversion mode as an inductive element configured to be the energy storage inductor in a switching regulator used for conditioning the power available from an internal power source to power for powering the device, and a controllable switch for switching between said communication mode and said power conversion mode. The communications system further comprises a controllable switch for connecting said inductive element to either said receiver or said power conversion circuit. The controllable switch switches the system between the communication mode and the power conversion mode by means of unipolar or bipolar transistor switches or by mechanical switches or relays. The communication system may be used in an in-vivo medical device.