A Compensation Amplifier with Automatic Zeroing and Stable Chopping

This paper proposes a compensation (or error) amplifier with rail-to-rail input and output ranges. The amplifier combines automatic zero adjustment technology and stable chopper to suppress its offset related ripple. Two rail-to-rail input fully differential operational amplifiers in parallel can realize that when one operational amplifier is in the amplification state, the other operational amplifier is in the feedback state. The two amplifiers are interleaved for common mode feedback adjustment, so that the whole compensation amplifier has different states: common mode feedback, offset sampling and amplification. An eight-frequency clock module is integrated in the compensation (or error) amplifier to supply power to each enable end of the amplifier. Finally, it outputs through the third amplifier, which makes the operational amplifier have the advantages of large bandwidth and high accuracy compared with the traditional operational amplifier.