1 Features

• Ultra-low 0.95nV/√Hz voltage noise

• High speed:

– 180MHz unity gain bandwidth

– 140MHz bandwidth at a gain of 2V/V (–1V/V)

– 105V/μs slew rate

• Very low distortion

– THD = –91dBc (f = 1MHz, RL = 150Ω)

– THD = –100dBc (f = 1MHz, RL = 1kΩ)

– THD+N = –137dBc (f = 1kHz, BW = 80kHz)

• Low 0.2mV (typical) and 1mV (maximum) input

offset voltage at 25°C

• 200mA output current drive (typical)

• Typical operation from ±4.5V to ±18V

• Offset nulling pins on the OPA891

2 Applications

• Low-noise, wide-band amplifier for industrial

applications

• Voltage-controlled oscillators

• Active filters

• Video amplifiers

• Cable drivers

• Ultrasound scanners

• Vector signal transceiver (VST)

• Professional audio mixer or control surface

• Professional microphones and wireless systems

• Professional speaker systems

• Professional audio amplifier

• Soundbar

• Turntable

• Professional video camera

• Guitar and other instrument amplifier

• Data acquisition (DAQ)

3 Description

The OPA891 and OPA2891 (OPAx891) are ultralow

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.