Intel Corporation
Low voltage class AB operational trans-conductance amplifier

Abstract:

Described is high-current drive class AB operational trans-conductance amplifier (OTA) output that can operate under low supply voltages (e.g., below 0.9 V) while maintaining desired functionality (e.g., reliable startup behavior, well-defined biasing currents, phase margins for improved stability) over a broad range of process, voltage, and temperature variations. The class AB OTA comprises a pre-amplifier stage, and a differential OTA output stage coupled to the pre-amplifier stage, wherein the differential OTA output stage comprises at least four folded cascode transistors.