Ripple reduction filter for chopped amplifiers

A system comprising:

• a chopped amplifier comprising an input terminal, an offset correction terminal, and an output terminal;
• and
• a ripple reduction filter comprising an input terminal and an output terminal, the input terminal of the ripple reduction filter coupled to the output terminal of the chopped amplifier and the output terminal of the ripple reduction filter coupled to the offset correction terminal of the chopped amplifier;
• wherein the output terminal of the ripple reduction filter generates a DC signal;
• wherein the ripple reduction filter further comprises:
• a bandpass filter comprising an input terminal and an output terminal, the input terminal of the bandpass filter coupled to the input terminal of the ripple reduction filter;
• and
• an amplitude limiter comprising an input terminal and an output terminal, the input terminal of the amplitude limiter coupled to the output terminal of the bandpass filter and the output terminal of the amplitude limiter coupled to the output terminal of the ripple reduction filter.

A ripple reduction filter comprising:

• an input terminal configured to receive a portion of an output signal of a chopped amplifier operating at a chopping frequency, the output signal of the chopped amplifier comprising a ripple, the ripple based on an offset voltage of the chopped amplifier;
• an output terminal configured to provide a feedback signal to the chopped amplifier, the feedback signal modifying the offset voltage of the chopped amplifier;
• a bandpass filter coupled to the input terminal, the bandpass filter configured to attenuate signals outside of a range of frequencies associated with the chopping frequency;
• and
• an amplitude limiter coupled to the bandpass filter and the output terminal, the amplitude limiter configured to receive an output signal of the bandpass filter and configured to amplify the output signal of the bandpass filter for signals having an amplitude below a predetermined threshold at a first level and not amplifying the output signal of the bandpass filter that exceeds the predetermined threshold, the amplitude limiter further configured to provide a signal corresponding to the limited ripple amplitude as the feedback signal.