Patent ID: 7479820

Claim:
A semiconductor device comprising a detector circuit that detects a level of a negative voltage, and a reference potential generating circuit that generates a reference potential, wherein said detector circuit includes a first voltage divider circuit including a plurality of MOS transistors connected in series between a potential of said negative voltage and a positive power-supply potential, said plurality of MOS transistors being configured to cause a voltage division between said negative voltage potential and said positive power-supply potential, and said first voltage divider circuit being configured to output a detect potential generated by the voltage division between said negative voltage potential and said positive power-supply potential; wherein said reference potential generating circuit includes a second divider circuit configured to generate said reference potential by obtaining an intermediate reference potential from a voltage division between said positive power-supply potential and ground; wherein said reference potential generating circuit further includes an adjustment circuit configured to decrease said intermediate reference potential by a predetermined adjustment value to obtain said reference potential; wherein said detector circuit further includes first and second level shift circuits that respectively shift said detect potential and said reference potential to predetermined potential levels; wherein said detector circuit further includes a comparator circuit that compares said level-shifted detect potential and said level-shifted reference potential respectively outputted by said first and second level shift circuits; wherein said semiconductor device further comprises a charge pump circuit being driven by an output signal from said comparator circuit and configured to generate said negative voltage in accordance with said reference potential; and wherein said detector circuit, said charge pump circuit, and said reference potential generating circuit form a negative voltage generating circuit that outputs said negative voltage.