The invention belongs to the technical field of analog IC (
Integrated Circuit) design, in particular to a high-bandwidth low-
power consumption frequency-compensation three-stage
operational amplifier. The
amplifier comprises an input stage, a second stage, an output stage, a
common mode feedback stage, a comprehension circuit, an internal feedforward circuit, wherein the second stage is connectedwith the input stage, the output stage is connected with the second stage and used for amplifying a
signal output by the second stage and driving an external
load circuit, the
common mode feedback stage extracts the common mode level of the differential output stage and stabilizes the common mode level, the comprehension circuit comprises a traditional trsanscondutance comprehension circuit, a miller comprehension circuit and a
resistor for separating a high-frequency zero pole, and the internal feedforward circuit is used for comprehending an internal additional pole and forming a push-pull circuit together with the output stage to reduce static
power consumption. The three-stage
operational amplifier realizes high
gain,
high bandwidth and high stability under the condition of little DC
power consumption and can be used in a high-speed analog-
digital conversion circuit, such as a sigma-
delta modulator suitable for the bandwidth of an LTE (Line Terminator Equipment)
wireless communication protocol.