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-to-digital converters (ADCs) or buffering the output of high-resolution digital-to-analog converters (DACs). The OPAx211 series is specified over a wide dual-power supply range of ±2.25 to ±18 V, or for single-supply 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.