Design ofa low-voltage rail-to-rail input and output operational amplifier with nested Miller compensation

A rail-to-rail constant g/sub m/ input and class-AB output operational amplifier in a 0.8-/spl mu/m double-poly, double-metal, n-well technology operating at a low supply voltage of 3.3 V is presented. A technique that uses nested Miller compensation yields 130 dB DC gain and 3.5 MHz unity gain frequency at a 10 k/spl Omega/ and 10 pF load. The class-AB output provides efficient quiescent current control and delivers output current to 1 k/spl Omega/ resistive load with low total harmonic distortion less than 0.1%. The die area of the operational amplifier is 0.15 mm/sup 2/.