A high-dynamic-range CMOS op amp with low-distortion output structure

In order to reach a high dynamic range, a rail-to-rail input structure was designed. With the output stage, the op amp has a completely symmetrical configuration. As a result, total harmonic distortion, especially the second harmonic distortion, of the op amp is minimized. Further, the structure allows the compensation of the right half-plane zero that normally appears in the commonly used two-stage Miller amplifier.