Chopper stabilized amplifier

An amplifier including differential inputs, and an output, the amplifier comprising:

• a low frequency path between the differential inputs and the output of the amplifier;
• a high frequency path between the differential inputs and the output of the amplifier;
• the low frequency path including a plurality of amplifier stages;
• choppers within the low frequency path that chop, at a chopping frequency, a differential signal at differential inputs and outputs of one of the amplifiers of the low frequency path to produce a chopped differential signal that has a DC offset of the one of the amplifier stages frequency shifted up to the chopping frequency;
• and
• a continuous time filter within the low frequency path, after the choppers, to attenuate chopper frequency ripple resulting from the chopping at the chopping frequency.

A method for use within an amplifier, comprising:

• chopping, at a chopping frequency, a differential signal at differential inputs and outputs of an amplifier stage to thereby produce a chopped differential signal that has a DC offset of the amplifier stage frequency shifted up to the chopping frequency;
• performing continuous time filtering, between a pair of further amplifier stages, to attenuate chopper frequency ripple resulting from the chopping at the chopping frequency;
• and
• allowing feedback through a compensation capacitor, yet preventing chopper frequency ripple from feeding forward through the compensation capacitor.

A method for use within an amplifier, comprising:

• chopping, at a chopping frequency, a differential signal at differential inputs and outputs of an amplifier stage to thereby produce a chopped differential signal that has a DC offset of the amplifier stage frequency shifted up to the chopping frequency;
• and
• performing continuous time filtering, between a pair of further amplifier stages, to attenuate chopper frequency ripple resulting from the chopping at the chopping frequency;
• wherein the amplifier includes differential inputs, an output, and a low frequency path and a high frequency path from the differential inputs to the output, and wherein the chopping, at the chopping frequency, occurs within the low frequency path.

An amplifier including differential inputs, and an output, the amplifier comprising:

• a low frequency path between the differential inputs and the output of the amplifier;
• a high frequency path between the differential inputs and the output of the amplifier;
• the low frequency path including a plurality of amplifier stages;
• choppers within the low frequency path that chop, at a chopping frequency, a differential signal at differential inputs and outputs of one of the amplifiers of the low frequency path to produce a chopped differential signal that has a DC offset of the one of the amplifier stages frequency shifted up to the chopping frequency;
• a filter within the low frequency path, after the choppers, to attenuate chopper frequency ripple resulting from the chopping at the chopping frequency;
• a buffer including an input and an output, the input of the buffer connected to the output of the amplifier;
• and
• a compensation capacitor connected between the output of the buffer and a node within the low frequency path;
• wherein the buffer allows feedback through the compensation capacitor, yet prevents chopper frequency ripple from feeding forward to the output of the amplifier through the compensation capacitor.