Patent ID: 7095269

Claim:
A voltage generator comprising: a voltage generator circuit that raises a level of an output voltage when a voltage level detection signal is a first logical level and that lowers the level of the output voltage when the voltage level detection signal is a second logical level; a first voltage level detection circuit generating a first detection signal in accordance with a first detection level, wherein the first voltage level detection circuit includes a logical level decision circuit that provides the first detection signal responsive to a potential at a detection node, a first current mirror circuit connected to a first potential source, the detection node and the voltage generator circuit, wherein the first current mirror circuit includes a first transistor having a first terminal connected to the first potential source, a second terminal, and a control terminal, and a second transistor having a first terminal connected to the detection node, a second terminal connected to a predetermined level that is changed according to the level of the output voltage, and a control terminal connected to the control terminal of the first transistor, and a second current mirror circuit connected to a second potential source, the detection node and the first current mirror circuit; a second voltage level detection circuit generating a second detection signal in accordance with a second detection level that is lower than the first detection level; and a selection circuit connected to the first and second voltage level detection circuits, wherein the selection circuit outputs a signal equivalent to the first detection signal as the voltage level detection signal when a power supply voltage level is equal to or higher than a first voltage level or when the power supply voltage level is equal to or lower than a second voltage level that is lower than the first voltage level, and wherein the selection circuit outputs a signal equivalent to the second detection signal as the voltage level detection signal when the power supply voltage level is lower than the first voltage level and higher than the second voltage level.