Patent ID: 7907902

Claim:
A semiconductor device comprising: an antenna; a protection circuit connected between a first terminal of the antenna and a second terminal of the antenna, the protection circuit comprising a switch; a rectifier circuit electrically connected to the antenna; and a comparison circuit configured to compare a voltage supplied by the rectifier circuit with a reference voltage and comprising: a diode, an anode of the diode being electrically connected to a node p, the node p being electrically connected to a first terminal of the rectifier circuit and a cathode of the diode being electrically connected to a second terminal of the rectifier circuit; a first transistor, a gate of the first transistor being electrically connected to the node p, and one of a source and a drain of the first transistor being electrically connected to the first terminal of the rectifier circuit; a second transistor, one of a source and a drain of the second transistor being electrically connected to the other of the source and the drain of the first transistor at a node q, and the other of the source and the drain of the second transistor being electrically connected to the second terminal of the rectifier circuit; wherein the gate of the second transistor is configured to be set at the reference voltage; and wherein the switch of the protection circuit is configured to control a passage of current in the protection circuit according to an electric potential of the node q.