VOLTAGE DETECTING CIRCUIT AND INTERNAL VOLTAGE GENERATING CIRCUIT COMPRISING IT

摘要

An internal voltage generating circuit for stably generating a required internal voltage and a voltage detecting circuit. The voltage detecting circuit comprises an insulated gate type field effect transistor the gate of which receives a reference voltage and a group of voltage drop devices connected between internal nodes in series with this insulation gate type field effect transistor. A reference voltage is generated by resistively dividing a source voltage including the threshold voltage and drop voltage of this insulation gate type field effect transistor as the voltage components. When the difference between the reference voltage and internal voltage exceeds a predetermined value, this group of voltage drop devices and the insulation gate type field effect transistor carry current, resulting in a decrease in detection node voltage and a detection of a decrease in the internal voltage. The reference voltage includes the threshold voltage of this transistor and the drop voltage of the group of voltage drop devices as the constituents. Dispersions in these parameters are cancelled to set a required voltage by resistive division.