1 Features

1• Precision with zero-crossover distortion:

– Low offset voltage: 150 μV (maximum)

– High CMRR: 114 dB

– Rail-to-rail I/O

• Wide bandwidth: 10 MHz

• Quiescent current: 650 μA/ch

• Single-supply voltage range: 2.2 V to 5.5 V

• Low input bias current: 0.2 pA

• Low noise: 9 nV/√Hz at 10 kHz

• Slew rate: 5 V/μs

• Unity-gain stable

2 Applications

• High-Z sensor signal conditioning

• Transimpedance amplifiers

• Test and measurement equipment

• Programmable logic controllers (PLCs)

• Motor control loops

• Communications

• Input, output ADC, and DAC buffers

• Active filters

3 Description

The OPA325, OPA2325, and OPA4325 (OPAx325)

are precision, low-voltage complementary metal-oxide

semiconductor (CMOS) operational amplifiers

optimized for very low noise and wide bandwidth,

while operating on a low quiescent current of only

650 μA.

The OPAx325 feature a linear input stage with zerocrossover

distortion that delivers excellent commonmode

rejection ratio (CMRR) of typically 114 dB over

the entire input range. The input common-mode

range extends 100 mV beyond the negative and

positive supply rails. The output voltage typically

swings within 10 mV of the rails.

The zero-crossover distortion, combined with wide

bandwidth (10 MHz), high slew rate (5 V/μs), and low

noise (9 nV/√Hz), make the OPAx325 a very good

successive-approximation register (SAR) analog-todigital

converter (ADC) input driver amplifier. In

addition, the OPAx325 have a wide supply-voltage

range from 2.2 V to 5.5 V, with excellent powersupply

rejection ratio (PSRR) over the entire supply

range, making the device an excellent choice for

precision, low-power applications that run directly

from batteries without regulation.

The OPA325 (single-channel version) is available in

the SOT23-5 package. The OPA2325 (dual-channel

version) is offered in SO-8 and MSOP-8 packages.

The OPA4325 (quad-channel version) is available in

TSSOP-14 package.