1 Features

• Ultra-low 0.95 nV/√ Hz voltage noise

• High Speed:

– 180-MHz unity gain bandwidth

– 140-MHz bandwidth [G = 2 (–1), –3 dB]

– 105-V/μs slew rate

• Very low distortion

– THD = –91 dBc (f = 1 MHz, RL = 150 Ω)

– THD = –100 dBc (f = 1 MHz, RL = 1 kΩ)

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

• Low 0.2-mV (typical) and 1-mV (max) input offset

voltage at 25°C

• 200-mA output current drive (typical)

• Typical operation from ±4.5 V to ±18 V

• 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 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 dualamplifier

OPA2891 offer very good ac performance

with 140-MHz bandwidth (G = 2), 105-V/μs slew

rate, and 70-ns settling time (0.1). The OPAx891

are unity-gain stable with 180-MHz bandwidth. These

amplifiers have a high drive capability of 200 mA and

draw only 7.5-mA supply current per channel. With

–100 dBc of total harmonic distortion (THD) at f =

1 MHz and a very low noise of 0.95 nV/√ Hz, the

OPAx891 are designed for applications requiring low

distortion and low noise such as buffering analog-todigital

converters.