Compact Single-Stage Input and Output Rail-to-Rail Class AB Buffer Amplifier With an Asymmetric Output Structure

This letter presents a compact single-stage buffer amplifier designed to drive a wide range of capacitive loads (CL). To further reduce power consumption and silicon area compared to previous single-stage rail-to-rail amplifiers, this letter proposes an asymmetric rail-to-rail class AB output structure. To achieve a high slew rate, the proposed amplifier employs positive feedback loops and a dynamic floating node. A prototype chip successfully drove a wide range of CL, from 250 pF to 15 nF, while achieving a fast transient response. The chip was fabricated using a 0.18- $\mu $ m CMOS process.