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 zero-crossover distortion that delivers
excellent common-mode 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-to-digital 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
power-supply 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
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.