1 Features
1• Low voltage noise: 1.1 nV/√Hz at 1 kHz
• Input voltage noise: 80 nVPP (0.1 to 10 Hz)
• THD + N: –136 dB (G = 1, ƒ = 1 kHz)
• Offset voltage: 125 μV (maximum)
• Offset voltage drift: 0.35 μV/°C (typical)
• Low supply current: 3.6 mA/Ch (typical)
• Unity-gain stable
• Gain bandwidth product:
– 80 MHz (G = 100)
– 45 MHz (G = 1)
• Slew rate: 27 V/μs
• 16-Bit settling: 700 ns
• Wide supply range:
– ±2.25 to ±18 V, 4.5 V to 36 V
• Rail-to-rail output
• Output current: 30 mA
• SON-8 (3 mm × 3 mm), VSSOP-8, and SOIC-8

2 Applications
• Ultrasound scanner
• Semiconductor test
• X-ray systems
• Lab and field instrumentation
• Data acquisition (DAQ)
• Radar
• Wireless communications test
• Seismic data acquisition
• DC power supply, ac source, electronic load
• Power analyzer
• Source measurement unit (SMU)

3 Description
The OPAx211 series of precision operational
amplifiers achieves very low 1.1-nV/√Hz noise density
with a supply current of only 3.6 mA. This series also
offers rail-to-rail output swing, which maximizes
dynamic range.
The extremely low voltage and low current noise,
high-speed, and wide output swing of the OPAx211
series make these devices an excellent choice as a
loop filter amplifier in PLL applications.
In precision data acquisition applications, the
OPAx211 series of operational amplifiers provides
700-ns settling time to 16-bit accuracy throughout 10-
V output swings. This ac performance, combined with
only 125 μV of offset and 0.35 μV/°C of drift over
temperature, makes the OPAx211 series a great
choice for driving high-precision 16-bit analog-todigital
converters (ADCs) or buffering the output of
high-resolution digital-to-analog converters (DACs).
The OPAx211 series is specified over a wide dualpower
supply range of ±2.25 to ±18 V, or for singlesupply
operation from 4.5 to 36 V.
The OPA211 is available in the small SON-8 (3 mm ×
3 mm), VSSOP-8, and SOIC-8 packages. The dual
version OPA2211 is available in a SON-8 (3 mm × 3
mm) or an SO-8 PowerPAD™ package. This series
of operational amplifiers is specified from TA = –40°C
to +125°C.