Patent ID: 6956781

Claim:
An amplifier comprising: an input node being shifted from a first power supply potential to a second power supply potential during a first mode in response to a selection signal, and for being maintained at the first power supply potential during a second mode; an amplification circuit connected to the input node for amplifying an electrical potential of the input node and outputting the amplified potential from a first output node in response to a control signal, the amplification circuit including: a first transistor having a first control electrode, a first electrode connected to a first power supply potential node or a second power supply potential node, and a second electrode connected to the first output node, a second transistor having a second control electrode connected to the first control electrode, a third electrode connected to the first power supply potential node or the second power supply potential node, and a fourth electrode connected to the second control electrode, a third transistor having a third control electrode connected to the input node, a fifth electrode connected to the second power supply potential node or the first power supply potential node, and a sixth electrode connected to the first output node, and a fourth transistor having a fourth control electrode applied an intermediate electrical potential between the first power supply potential and the second power supply potential, a seventh electrode connected to the second power supply potential node or the first power supply potential node, and an eighth electrode connected to the fourth electrode; and a constant voltage circuit connected to the first output node for stabilizing the electrical potential of the first output node and outputting the stabilized potential from a second output node, the constant voltage circuit including: a fifth transistor having a fifth control electrode connected to the second output node, a ninth electrode connected to the first power supply potential node, and a tenth electrode connected to the fifth control electrode, a sixth transistor having a sixth control electrode connected to the first output node, an eleventh electrode connected to the input node, and a twelfth electrode connected to the tenth electrode, and a pull-down element connected between the input node and the second power supply potential node.