An amplifier circuit comprises a first operational transconductance (OTA)
having an input and an output and a second OTA having an input that
communicates with an output of the first OTA. A third OTA has an input
that communicates with an input of the first OTA. A fourth OTA has an
input that communicates with an output of the third OTA and an output
that communicates with the input of the second OTA. A switched
capacitance circuit selectively couples a capacitance to at least one of
the input of the third OTA and the output of third OTA.