Feedforward Reversed Nested Miller Compensation Techniques for Three-Stage Amplifiers

Abstract

Two novel reversed nested Miller compensation (RNMC) techniques for low-voltage three-stage amplifiers are proposed in this contribution: Nested Feedforward RNMC (NFRNMC) and Crossed Feedforward RNMC (CFRNMC). Both techniques employ double feedforward paths to remove the right-half-plane zero. The second architecture generates a left-half-plane zero to further improve the phase margin. To demonstrate advantages of the new RNMC techniques over the traditional RNMC architecture, two three-stage amplifiers are designed employing the proposed techniques in a standard 0.5 /spl mu/m CMOS process. Simulation results show that, with the same gain-bandwidth product, the NFRNMC and CFRNMC amplifiers have improved stabilities over the conventional RNMC amplifiers by more than 150 and 200 in the phase margin, respectively. They both dissipate less than 0.4 mW of power with a 1 V supply.