Patent ID: 8232838

Claim:
An amplifier comprising: an amplifier circuit to support a differential input; a ripple discharge circuit to lower ripple terminal voltage for generating reference voltage of the amplifier circuit based on a source voltage of the amplifier circuit; and a ripple control circuit to control discharge timing by the ripple discharge circuit based on potential difference between the source voltage and the ripple terminal voltage, wherein in a case that the source voltage is lowered and the potential difference between the source voltage and the ripple terminal voltage is below a constant potential difference, the ripple terminal voltage is lowered until the ripple terminal voltage reaches a first threshold value when a lowered value of the source voltage is equal to or larger than a predetermined voltage that exceeds the first threshold value by the constant potential difference, and the ripple terminal voltage is lowered until the ripple terminal voltage reaches a second threshold value smaller than the first threshold value when the lowered value of the source voltage is below the predetermined voltage.