A semiconductor device comprising a passive magnetoelectric transducer structure adapted for generating a charge via mechanical stress caused by a magnetic field. The first transducer structure has a first terminal electrically connectable to the control terminal of an electrical switch, and having a second terminal electrically connectable to the first terminal of the electrical switch for providing a control signal for opening/closing the switch. The switch may be a FET. A passive magnetic switch using a magnetoelectric transducer structure. Use of a passive magnetoelectric transducer structure for opening or closing a switch without the need for an external power supply.