Patent ID: 6144256
Filing Date: 2000-11-07
Classification: H03F

Abstract:
An audio amplifier comprising:a voltage feedback amplifier stage consisting of an operational amplifier having an audio signal input connected to the non-inverting input of said operational amplifier and a voltage divider connected to the inverting input of said operational amplifier;a push-pull voltage gain/phase splitter stage driven from said voltage feedback amplifier stage;a bias adjustment stage driven from said push-pull voltage gain/phase splitter stage;a current drive stage driven from said bias adjustment stage;an output stage driven from said current drive stage, said output stage comprising a plurality of paralleled current shared individual MOS output transistors driving an output node;an output load having a first terminal connected to said output node and a second terminal connected to a fixed voltage potential;a first voltage feedback loop comprising a voltage feedback stage having an input connected to said voltage divider driven from said first terminal of said load and an output connected to a feedback input node in said voltage feedback amplifier stage;a second voltage feedback loop comprising a voltage feedback stage having an input connected to said output node and an output connected to a feedback input node in said push-pull voltage gain/phase splitter stage; anda third feedback loop comprising a current feedback stage having an input in series between said output node and said load and an output connected to a feedback input node in said voltage feedback amplifier stage.