1 Features
• Precision with zero-crossover distortion:
– Low offset voltage: 50μV (maximum)
– High CMRR: 120dB
– Rail-to-rail I/O
• Wide bandwidth: 40MHz
• Low input bias current: 1pA (maximum)
• Low noise: 6.1nV/√Hz at 10kHz
• Slew rate: 30V/μs
• Fast 0.01% settling time: 180ns
• Single-supply voltage range: 2.2V to 5.5V
• Unity-gain stable

2 Applications
• Optical module
• Position sensor
• Multiparameter patient monitor
• CT and PET scanner
• Chemistry and gas analyzer
• Bidirectional 400-V and 800-V to LV
• Merchant network and server PSU
• String inverter
• Solar power optimizer

3 Description
The single-channel OPA328, dual-channel OPA2328
and quad-channel OPA4328 (OPAx328) are a new
generation family of precision, low-voltage CMOS
operational amplifiers optimized for very low noise
and wide bandwidth.
The OPAx328 have a linear input stage with zerocrossover
distortion that delivers excellent commonmode
rejection ratio (CMRR) of 120dB (typical) over
the full input range. The input common-mode voltage
range extends 100mV beyond the negative and
positive supply rails. The output voltage typically
swings within 10mV of the rails.
The OPAx328 also use Texas Instrument's proprietary
e‑trim™ operational amplifier technology, enabling a
unique combination of ultra-low offset and low input
offset drift without the need for any input switching or
auto-zero techniques.
Low-noise (6.1nV/√Hz) and high-speed operation
(40MHz, 30V/μs) make these devices a great choice
for driving sampling analog-to-digital converters
(ADCs).
The OPAx328 are also a great choice for highimpedance-
input, single-supply applications. Low
input bias current and low input capacitance allows
for high-frequency transimpedance gains at low
photocurrent operation (< 1nA).