The OPA891 and OPA2891 (OPAx891) are ultra-low voltage noise, high-speed voltage feedback amplifiers that are an excellent choice for applications requiring low voltage noise, including communications and imaging. The single-amplifier OPA891 and the dual-amplifier OPA2891 offer very good ac performance with 140MHz bandwidth, gain (G) = 2V/V, 105V/µs slew rate, and 70ns settling time (0.1%). The OPAx891 are unity-gain stable with 180MHz bandwidth. These amplifiers have a high drive capability of 200mA and draw only 7.5mA supply current per channel. With –100dBc of total harmonic distortion (THD) at f = 1MHz and a very low noise of 0.95nV/√Hz, the OPAx891 are designed for applications requiring low distortion and low noise such as buffering analog-to-digital converters.