High Gain Single-Stage Rail-to-Rail Ampli�er With Nested-Current-Mirror

A power efficient, high DC gain, gain-bandwidth product (GBW) and slew rate (SR) rail-to-rail output single-stage ampli�ers are replacement of their multi-stage amplifier, especially for LCD display applications that are used in large numbers in their column drivers as a buffer. This paper represents Positive Feedback Nested-Current-Mirror Single-Stage Rail-to-Rail Ampli�er to achieve high of DC gain, Speci�cally, NCM is customizable for different mirror steps, and sub mirror ratios, to balance the performance metrics and capacitive- load (CL) at the output of column driver to get high driving capability under rail-to-rail output swing. Analytical treatments of the Positive feedback NCM technique in terms of performance limits and robustness reveal that the NCM ampli�er can surpass the fundamental power-efficiency limit set by the basic differential-pair (DP) ampli�er. A prototypes 3-step Positive feedback NCM ampli�ers were analyzed with 88 dB DC gain and 0.0028–0.27 MHz GBW over 0.15–15 nF with 86 approx phase margin (PM) with power consumption power 144µW for the load of .15nF.