Amplifiers operating under low-voltage and low-power conditions are strongly limited in dynamic range and bandwidth. The maximum dynamic range is limited by the supply power and the thermal noise power in resistors. To obtain the maximum, input and output stages should be able to process signals from rail to rail. Several rail-to-rail input stages and rail-to-rail output stages biased in current-efficient class-AB mode are presented. Also, the bandwidth is limited by the low-power constraint. To reach the maximum bandwidth at sufficient DC gain, the effectivity of several frequency compensation structures is compared, such as Parallel, Miller, and Nested Miller Compensation. Finally, it is shown that the Multipath Nested Miller Compensation combines a very high bandwidth with high gain, while being insensitive to process parameters.