US Patent 7592871 Fully differential current-feedback CMOS/bipolar operational amplifier

A differential current amplifier circuit includes a first circuit generating a first pair of output currents based on a first input current to the differential current amplifier circuit. A second circuit generates a second pair of output currents based on a second input current to the differential current amplifier circuit. A first subtraction circuit generates a first output voltage based on a difference between one of the first pair of output currents and one of the second pair of output currents. A second subtraction circuit generates a second output voltage based on a difference between the other one of the second pair of output currents and the other one of the first pair of output currents.