Patent ID: 7764118

Claim:
A chopper-stabilized amplifier, comprising: a main signal path, comprising: an input chopping circuit which receives a differential input signal and chops said input signal in response to a chopping clock, said chopped input signal provided at said input chopping circuit's output; a first transconductance amplifier connected to receive said input chopping circuit's output at its input and to produce a first differential output which varies with its input; an output chopping circuit which receives the first differential output from said first transconductance amplifier and chops said first differential output in response to said chopping clock, said chopped first differential output signal provided at said output chopping circuit's output; and a second transconductance amplifier connected to receive said output chopping circuit's output at its input and to produce an output which varies with its input; and an auto-correction feedback loop, comprising: a third transconductance amplifier connected to receive said output chopping circuit's output at its input and to produce a third differential output which varies with its input; a third chopping circuit which receives the third differential output from said third transconductance amplifier and chops said third differential output in response to said chopping clock, said chopped third differential output signal provided at said third chopping circuit's output; a filter arranged to filter said third chopping circuit's output so as to substantially reduce the AC component present in said chopped third differential output signal and to provide said filtered version of said third chopping circuit's output at an output; and a fourth transconductance amplifier connected to receive said filtered version of said third chopping circuit's output at its input and to produce a fourth differential output which varies with its input, said fourth differential output coupled to said first differential output, said auto-correction feedback loop arranged to suppress transconductance amplifier-related offset voltages and offset voltage-induced ripple that might otherwise be present in said output chopping circuit's output.