Patent ID: 6552606
Filing Date: 2003-04-22
Classification: H03F

Abstract:
An amplifier circuit for amplifying electric signals comprising controllable switching means for generating a block wave signal whose amplitude varies between first and second supply voltage values during operation, filter means for filtering said block wave signal so as to produce an output signal, said filter means comprise a selfinductance and a capacitance, means for providing a filter capacitance current proportional to a current through said filter capacitance, modulating means for pulse width modulation of said block wave signal by driving said switching means in response to an input signal to be amplified, and correction means for providing from a reference value derived from said input signal and an output signal value proportional to said output signal a correction signal for controlling said modulating means, and means for deriving a reference current from said input signal, wherein said correction means are arranged for providing said correction signal as a current correction signal from said reference current and said filter capacitance current.