Design of a Multistage Amplifier with Active Feedback Compensation

Based on the basic reversed nested miller compensation,a new technique is presented in this paper,which makes use of transconductance with capacitance. And the new technique shows an inherent advantage when driving heavy capacitive loads. Threestage amplifier is implemented by a standard 0.5-um CMOS process and simulated with Hspice. When driving a 500-pF capacitive load,the amplifier achieves 120-dB dc gain,2.4-MHz GBW,60°phase margin,and 1.3V/us average slew rate,while only dissipating 0.45-mW power at ±1.5V supply.