A Three-Stage Amplifier with Single-Miller Capacitor Compensation

A three-stage amplifier with a new compensation method was designed so as to meet the needs of low voltage circuits.This new compensation method combines the single Miller-capacitor compensation and the crossed feedforward reversed nested Miller compensation together,using the zeros formed by the feedforward path to compensate the poles in the main path.Using TSMC 0.18um CMOS technology,the circuit has a DC gain about 113 dB,a PM of 87 degree and the power dissipation is just 0.534 mW with a 120 pF capacitor load.The compensation is effective and the op-amp has a great gain and a large PM.