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.