Patent ID: 6441685
Filing Date: 2002-08-27
Classification: H03F

Abstract:
An amplifier circuit for driving a load, the amplifier circuit comprising:at least one amplifier stage that receives an input signal and amplifies the input signal to produce at least one amplified signal: a first lowpass filter, operably coupled between an output of the at least one amplifier stage and the load; a highpass filter, operably coupled to an input of the first lowpass filter, the highpass filter producing a first filtered feedback signal; a second lowpass filter, operably coupled to an output of the first lowpass filter, the second lowpass filter producing a second filtered feedback signal, the second lowpass filter having a cutoff frequency which is substantially lower than a cutoff frequency of said first lowpass filter; and a summing arrangement, operably coupled to the second lowpass filter, the highpass filter, and an input of the at least one amplifier stage, that combines the first filtered feedback signal and the second filtered feedback signal to produce a composite feedback signal, the composite feedback signal being combined with the input signal to apply negative feedback to the at least one amplifier stage.