The  ISL28291 is a tiny, dual, ultra-low noise, ultra-low distortion operational amplifier. It is fully specified to operate down to +3V single supply. This amplifier has outputs that swing rail-to-rail and an input common mode voltage that extends to ground (ground sensing). The device is unity gain stable with an input referred voltage noise of 1.7nV/√Hz. Both parts feature 0.00018% THD+N at 1kHz. The ISL28291 is available in the 8 Ld SOIC, 10 Ld 1.8mm x 1.4mm UTQFN and 10 Ld MSOP packages. All devices are guaranteed over -40 °C to +125 °C.


  • 1.7nV/√Hz input voltage noise at 1kHz
  • 1kHz THD+N typical 0.00018% at 2VP-P VOUT
  • Harmonic Distortion -76dBc, -70dBc, fo = 1MHz
  • 61MHz -3dB bandwidth
  • 630µV maximum offset voltage
  • 3µA input bias current
  • 100dB typical CMRR
  • 3V to 5.5V single supply voltage range
  • Rail-to-rail output
  • Ground sensing
  • Enable pin (not available in the 8 Ld SOIC package option)
  • Pb-free (RoHS compliant)


  • Low noise signal processing
  • Low noise microphones/preamplifiers
  • ADC buffers
  • DAC output amplifiers
  • Digital scales
  • Strain gauges/sensor amplifiers
  • Radio systems
  • Portable equipment
  • Infrared detectors

Product Options

Part Number Part Status Pkg. Type Carrier Type MOQ Buy Sample
Active SOICN Tube 97
Active SOICN Reel 1000
Active uTQFN Reel 3000
Active MSOP Tube 50
Active MSOP Reel 1500

Documentation & Downloads

Title language Type Format File Size Date
Datasheets & Errata
ISL28191, ISL28291 Datasheet Datasheet PDF 1.99 MB
User Guides & Manuals
ISL2829xEVAL1Z, ISL5529xEVAL1Z User Guide Manual PDF 393 KB
Application Notes & White Papers
How to Bias Op-Amps Correctly Application Note PDF 263 KB
AN1993: Voltage Feedback versus Current Feedback Operational Amplifiers Application Note PDF 564 KB
AN1299: Measuring RF Interference in Audio Circuits Application Note PDF 679 KB
AN1548: Designer's Manual for the iSim Active Filter Designer Application Note PDF 8.19 MB
AN1613: From SPICE Netlist to Allegro Design Sub-Circuit Application Note PDF 1.02 MB
AN1560: Making Accurate Voltage Noise and Current Noise Measurements on Operational Amplifiers Down to 0.1Hz Application Note PDF 2.04 MB
AN1561: Radiated Interference in Audio Circuits Application Note PDF 556 KB
AN1556: Building an Accurate SPICE Model for Low Noise, Low Power Precision Amplifiers Application Note PDF 976 KB
AN1694: The Four Basic Building Blocks of an Op Amp Application Note PDF 357 KB
AN535: Design Considerations for a Data Acquisition System (DAS) Application Note PDF 843 KB
PCN12094 - Alternate Manufacturing Site for Assembly of the Listed Intersil Packaged Products - Amkor Technology, Philippines (ATP) Product Change Notice PDF 98 KB
PCN12085 - 8l, 14l, 16l SOIC w/ Gold Bond Wire @ ATP as Alternate Assembly Site Product Change Notice PDF 152 KB
PCN12084 - Manufacturing Site Change for the Listed Intersil Products - Carsem (CAS) Ipoh Malaysia Product Change Notice PDF 135 KB
PCN11059 - Shipping Tube Change for Intersil MSOP Packaged Products Product Change Notice PDF 117 KB
PCN10114 - Part Marking Configuration Change for Intersil TDFN, uTDFN, and uTQFN Packaged Products Product Change Notice PDF 205 KB
isl28191 Model TXT 5 KB
Analog ICs Brochure 日本語 Brochure PDF 4.20 MB
TB514: Operational Amplifier Basics Other PDF 519 KB
PA14045 - Data Sheet Specification Change for Intersil Product ISL28191* and ISL28291* Product Advisory PDF 291 KB
PA14042 - Minimum Line Quantity Change Product Advisory PDF 363 KB
General-purpose operational amplifiers and comparators Pamphlet ( D18268EJ2V0PF00 ) Flyer PDF 1.11 MB

Boards & Kits

Part Number Title Type Company
ISL28290EVAL1Z Dual Supply Ultra-Low Noise RRIO Op Amp Evaluation Board Evaluation Renesas
ISL28291EVAL1Z Dual Supply Ultra-Low Noise RRIO Op Amp Evaluation Board Evaluation Renesas