Patent ID: 7663437

Claim:
An operational amplifier comprising: four internal circuit nodes N 1 , N 2 , N 3 , and N 4 ; a differential pair configured for receiving a differential input signal and for steering a first output current and a second output current into N 1 and N 2 , respectively; a first circuit branch, coupled between N 1 and N 3 ; a second circuit branch, substantially identical to the first circuit branch, coupled between N 2 and N 4 ; a first current-mode circuit comprising a first group of commutable current source pairs controlled by a first group of logical signals, respectively, each commutable current source pair steering two currents either in a straight manner onto N 1 and N 2 , respectively, or in a commutated manner onto N 2 and N 1 , respectively, depending on a state of a respective logical signal; and a second current-mode circuit comprising a second group of commutable current source pairs controlled by a second group of logical signals, respectively, each commutable current source pair steering two currents either in a straight manner onto N 3 and N 4 , respectively, or in a commutated manner onto N 4 and N 3 , respectively, depending on a state of a respective logical signal.