Ripple reduction method for chopper amplifiers

A method, comprising:

• receiving a differential input signal;
• processing the differential input signal to produce a modulated differential signal;
• processing the modulated differential signal to produce an amplified differential signal configured to compensate for an amplifier offset, wherein processing the modulated differential signal causes a ripple in the amplified differential signal;
• processing the amplified differential signal to produce a demodulated differential signal, wherein a portion of the demodulated differential signal resulting from the differential input signal has a first frequency, and wherein a portion of the demodulated differential signal resulting from the ripple has a second frequency;
• filtering the compensated signal through a filter to compensate for at least part of the ripple at the second frequency;
• integrating the filtered demodulated differential signal to produce an integrated differential signal configured to compensate for at least part of the ripple;
• and
• attenuating the integrated differential signal to reduce a peak-to-peak voltage of the ripple.

An electrical circuit, comprising:

• a modulating chopper configured to:
• receive a differential input signal at a first frequency;
• and
• modulate the differential input signal to a second frequency to form a modulated differential signal;
• a null amplifier coupled to the modulating chopper and configured to amplify the modulated differential signal to form an amplifier output, wherein amplifying the modulated differential signal causes a ripple in the amplifier output;
• a demodulating chopper coupled to the null amplifier and configured to demodulate the amplifier output to form a demodulated differential signal having a first portion at the first frequency and a second portion at a third frequency;
• an integrator coupled to the demodulating chopper and configured to integrate the demodulated differential signal to form an integrated differential signal;
• and
• an attenuator coupled to the integrator and configured to attenuate the integrated differential signal to form an attenuated differential signal to compensate for at least a portion of the ripple,
• wherein the electrical circuit is coupled to an amplifier via a secondary amplifier path and configured to transmit the attenuated differential signal to the amplifier via the secondary amplifier path to compensate for an offset on a first amplifier path of the amplifier.