Nonlinear class AB input stage

摘要

A circuit includes a differential input stage amplifier that receives a differential input voltage and generates an output voltage based on a difference in the differential input voltage. A feedback loop provides feedback from an output of the differential input stage amplifier to input tail current of the differential input stage amplifier. The feedback loop enables class AB operation of the differential input stage amplifier. At least one gain reducer is operatively coupled to the feedback loop to reduce the gain of the feedback loop. The gain reducer has a resistance value that varies inversely proportional to loop current in the feedback loop to reduce the gain of the feedback loop as loop current increases.

主权项

1. A circuit comprising:
a differential input stage amplifier that receives a differential input voltage and generates an output voltage based on a difference in the differential input voltage; a feedback loop to provide feedback from an output of the differential input stage amplifier to an input tail current of the differential input stage amplifier, wherein the feedback loop enables class AB operation of the differential input stage amplifier; and at least one gain reducer operatively coupled to the feedback loop to reduce a gain of the feedback loop, wherein the gain reducer has a resistance value that varies inversely proportionally to a loop current in the feedback loop to reduce the gain of the feedback loop as the loop current increases, wherein the circuit is configured as a low dropout linear regulator where the differential input voltage includes a reference voltage component and a feedback component supplied from an output of the regulator.