Patent ID: 7432761

Claim:
An amplifier circuit, comprising: a differential circuit which generates an amplification voltage corresponding to a difference between an input voltage and a reference voltage; a first output circuit which generates a first output signal upon receipt of input of the amplification voltage from said differential circuit; a second output circuit which generates a second output signal upon receipt of input of the amplification voltage from said differential circuit; and a selector circuit which selects either the said first output circuit or said second output circuit, wherein when said first output circuit is selected by said selector circuit, said first output circuit outputs a voltage corresponding to the amplification voltage from said differential circuit and said second output circuit outputs a predetermined fixed voltage, wherein when said second output circuit is selected by said selector circuit, said second output circuit outputs a voltage corresponding to the amplification voltage from said differential circuit and said first output circuit outputs a predetermined fixed voltage, wherein said first output circuit includes a first clamp circuit which generates a clamp voltage so that the first output signal does not become a predetermined clamp voltage or below, irrespective of the amplification voltage from said differential circuit, and said first output circuit outputs the first output signal with a nonzero voltage in the event that the input voltage is equal to the reference voltage, and wherein said second output circuit includes a second clamp circuit which generates a clamp voltage so that the second output signal does not become a predetermined clamp voltage or below, irrespective of the amplification voltage from said differential circuit, and said second output circuit outputs the second output signal with a nonzero voltage in the event that the input voltage is equal to the reference voltage.