1. Field of the Invention
The present invention relates generally to operational amplifiers and, more particularly, to analog-to-digital converter systems that include such amplifiers.
2. Description of the Related Art
Operational amplifiers generally position one or more stages of differential pairs of transistors in arrangements which seek to realize a high open-loop gain. In typical uses of these amplifiers, feedback structures are looped about them to lower and broaden a resulting closed-loop response. Various compensation structures have been proposed for operational amplifiers to enhance the stability of this closed-loop response. It has often been found, however, that various amplifier parameters (e.g., bandwidth, phase margin and headroom) do not meet desired performance levels. This has been especially the case when the operational amplifiers drive capacitive loads.