Patent ID: 8482351

Claim:
A power amplifier, comprising: an operation amplifier stage, at least one buffer stage and an output stage which are consecutively connected with each other; wherein the operation amplifier stage has a positive input end connected to a signal source, for receiving a signal to be amplified, and a negative input end for receiving a feedback signal; a first feedback unit connected between an output end of the output stage and the negative input end of the operation amplifier stage, and configured to provide a first feedback signal to perform a closed-loop negative feedback on an output of the power amplifier; a second feedback unit connected between an input end of the output stage and the negative input end of the operation amplifier stage, and configured to provide a second feedback signal to compensate phase lag caused by capacitance input by the input end of the output stage; and a third feedback unit connected between an input end of the at least one buffer stage and the negative input end of the operation amplifier stage, and configured to provide a third feedback signal to compensate phase lag caused by capacitance input by the input end of the buffer stage; the first, second and third feedback signals respectively provided by the first feedback unit, the second feedback unit and the third feedback unit are superposed at the negative input end of the operation amplifier stage.