Patent ID: 8059437

Claim:
An integrated circuit comprising: a semiconductor substrate; a shielding layer; a circuit element formed on the shielding layer; a functional circuit carrying out a specified operation with the use of the circuit element; and an n-channel MOS transistor, wherein the shielding layer is connected either to a reference potential of the functional circuit or to a point having an electric potential that changes in accordance with a change in the reference potential, and the reference potential is changed by turning the MOS transistor on and off; wherein the MOS transistor has a drain terminal, to which an input voltage is applied, and has a gate terminal and a source terminal; wherein the source terminal of the MOS transistor is connected to a coil, and the coil is connected to a capacitor, to which capacitor an output voltage is applied, wherein the functional circuit is connected to the gate terminal of the MOS transistor, and carries out an operation with the use of the circuit element, and wherein the MOS transistor is driven by the functional circuit for obtaining a specified output voltage from the input voltage.