Broadband current operational amplifier in assembly line ADC (Analog to Digital Converter)

The invention relates to the field of operational amplifiers, in particular to a broadband current operational amplifier in an assembly line ADC (Analog to Digital Converter). The main body of the broadband current operational amplifier is of a foldable gain-enhancement structure. A BN and a BP are taken as auxiliary operational amplifiers, wherein the BN is a current auxiliary operational amplifier, and the BP is of a conventional foldable cascode structure. A current common-mode feedback circuit is connected to the drains of M1 and M2 of a main operational amplifier, and the common-mode level of an output signal is adjusted by adjusting main operational amplifier branch current. Through adoption of the broadband current operational amplifier, the output swing is enhanced; the parasitic capacitance on a signal main channel is reduced; and the circuit speed of the whole operational amplifier is increased. When the operational amplifier is applied to a video processing ADC, the speed of the ADC can be increased, and the requirement on video processing can be met. The broadband current operational amplifier has the characteristics of low power consumption, large dynamic range and the like.