Patent ID: 7429887

Claim:
A substrate voltage regulating circuit for regulating a substrate voltage of a MOSFET of an integrated circuit main body by outputting a voltage to a substrate of said MOSFET so that the drain current of said MOSFET is constant, comprising: a limiting means for limiting the upper and lower values of said voltage outputted to said substrate of said MOSFET, wherein said MOSFET is a p-type monitoring MOSFET, the upper limit of the output voltage value of said substrate voltage regulating means is set to a voltage equal to or above supply potential of said integrated circuit main body and within a range where the GIDL effects do not occur in said p-type monitoring MOSFET, and the lower limit of the output voltage value of said substrate voltage regulating means is set to a voltage below the supply potential of said integrated circuit main body and within a range where said p-type monitoring MOSFET does not show the bipolar characteristic.