Patent ID: 7974111

Claim:
A semiconductor device comprising: a DC/DC converter including; n number of diodes connected in series between an input terminal and an output terminal of the DC/DC converter (n: an integer, 3≦n), (n−1) number of capacitors each including a first electrode and a second electrode, wherein the first electrode of one of the (n−1) number of capacitors is connected to an output terminal of one of n number of diodes, a circuit to supply a first potential from an antenna and connected to the input terminal of the DC/DC converter; a potential supply circuit to supply a second potential from a secondary battery or a third potential selectively and connected to the second electrodes of the (n−1) number of capacitors; and wherein the potential supply circuit is a circuit by which the third potential is supplied to the second electrode of a (2k−1)-th capacitor when the second potential is supplied to the second electrode of a 2k-th capacitor (k: an integer, 2k≦n−1 and 2k−1≦n−1), and by which the second potential is supplied to the second electrode of the (2k−1)-th capacitor when the third potential is supplied to the second electrode of the 2k-th capacitor.