Patent ID: 9671805
Date: 2017-06-06
CPC Classifications: G05F,H03F

Claim:
1. An amplifier comprising a first amplification stage configured to provide an intermediate voltage, based on an outer feedback voltage and based on a reference voltage; an output stage configured to provide a load current at an output voltage based on the intermediate voltage; and an outer feedback circuit configured to derive the outer feedback voltage from the output voltage; wherein the output stage comprises a buffer configured to provide a drive voltage based on the intermediate voltage and based on an inner feedback voltage derived from the output voltage; and wherein the buffer comprises a pass device configured to provide the load current at the output voltage based on the drive voltage, and wherein the first amplification stage comprises a differential amplification stage; the differential amplification stage comprises a differential transistor pair, and is configured to provide the intermediate voltage at a stage output node of the differential transistor pair, based on the outer feedback voltage at a first stage input node and based on the reference voltage at a second stage input node; the differential transistor pair further comprises a current feedback node; the differential amplification stage further comprises an active load comprising a diode transistor directly coupled to the current feedback node and a mirror transistor coupled to the stage output node, wherein the current feedback node comprises a drain of the diode transistor; and the amplifier further comprises a current feedback network configured to provide a feedback current to the current feedback node, in dependence of a voltage at the pass device.