Patent ID: 8035134

Claim:
A semiconductor integrated circuit including a plurality of functional blocks, wherein: a substrate voltage input terminal of an insulated-gate field effect transistor of a first conductivity type included in a first functional block and a source voltage input terminal of an insulated-gate field effect transistor of a second conductivity type included in the first functional block are respectively connected with a substrate voltage input terminal of an insulated-gate field effect transistor of the second conductivity type included in a second functional block and a source voltage input terminal of an insulated-gate field effect transistor of the first conductivity type included in the second functional block; and a plurality of constant voltage circuits, each of which supplies predetermined voltages to a substrate voltage input terminal of an insulated-gate field effect transistor of the first conductivity type included in one of the plurality of functional blocks or to a source voltage input terminal of an insulated-gate field effect transistor of the second conductivity type included in the one of the plurality of functional blocks, wherein at least one of the plurality of constant voltage circuits includes four voltage output terminals connected to the source voltage input terminals and the substrate voltage input terminals of the insulated-gate field effect transistors of the first and second conductivity types included in one of the plurality of functional blocks, respectively, and a voltage selected according to an input signal is output from each of the four voltage output terminals.