OPA683pdf datasheet (Very Low

The OPA683 provides a new level of performance in very low-power, wideband, current feedback amplifiers. This CFBplus amplifier is among the first to use an internally closed-loop input buffer stage that enhances performance significantly over earlier low-power CFB amplifiers. While retaining the benefits of very low power operation, this new architecture provides many of the advantages of a more ideal CFB amplifier. The closed-loop input stage buffer gives a very low and linearized impedance path at the inverting input to sense the feedback error current. This improved inverting input impedance gives exceptional bandwidth retention to much higher gains and improved harmonic distortion over earlier solutions limited by inverting input linearity.