High efficiency class AB transconductance amplifier

摘要

A class AB transconductance amplifier (200) has first and second differential input amplifier stages (100-112) adapted for receiving first and second differential input signals (Vin+, Vin-). First and second input cascode stages are coupled to the first and second differential input amplifier stages for providing first and second differential folded cascode signals. An output stage (113-118) is coupled to the first and second differential folded cascode signals providing an output signal indicative of a difference between the first and second differential input signals (Vin+, Vin-). A bias stage (101, 102) is coupled to said first and second differential input amplifier stages (103-104, 105-106) and the first and second input cascode stages bias the first and second differential input amplifier stages (100-112) to operate as a class AB folded cascode amplifier circuit (200). The bias stage generates class AB biasing signals.