Patent ID: 8330542

Claim:
Power amplifier for amplifying an electric input signal in an operational frequency range and providing an output signal, comprising switching means ( 12 ) for generating a block wave signal by alternately switching the block wave signal to a first supply voltage or a second supply voltage, filter means ( 14 , 16 ) for generating a power output signal by low pass filtering the block wave signal, input means for receiving the electric signal and driving the switching means, wherein the input means comprises an integrator circuit ( 10 ) generating an error signal formed by a difference between the output signal and the electric input signal and providing an integrator gain in the operational frequency range, the power amplifier further comprising a local feedback circuit ( 18 ) connecting the output signal to an input of the switching means, and a global feedback circuit ( 20 ) connecting the output signal to a first input of the integrator circuit ( 10 ), an output of the integrator circuit being connected to the input of the switching means, characterised in that a limiter circuit ( 22 ) is connected to receive the electric input signal and an output signal of the integrator circuit and connected to the integrator circuit for limiting the gain of the integrator circuit when detecting a difference between the electric input signal and the output signal of the integrator circuit exceeding a predetermined value.