1. Products
  2. Amplifiers
  3. Operational Amplifiers (Op Amps)
  4. Low Input Bias Current Op Amps (≤100 pA)
  5. AD820


Features and Benefits

  • True single-supply operation
    Output swings rail-to-rail
    Input voltage range extends below ground
    Single-supply capability from 5 V to 36 V
    Dual-supply capability from ±2.5 V to ±18 V 
  • Excellent load drive
    Capacitive load drive up to 350 pF
    Minimum output current of 15 mA 
  • Excellent ac performance for low power
    800 μA maximum quiescent current
    Unity-gain bandwidth: 1.8 MHz
    Slew rate of 3 V/μs 
  • Excellent dc performance
    800 μV maximum input offset voltage
    2 μV/°C typical offset voltage drift
    25 pA maximum input bias current 
  • Low noise: 13 nV/√Hz @ 10 kHz 

Product Details

The AD820 is a precision, low power FET input op amp that can operate from a single supply of 5 V to 36 V, or dual supplies of ±2.5 V to ±18 V. It has true single-supply capability, with an input voltage range extending below the negative rail, allowing the AD820 to accommodate input signals below ground in the single-supply mode. Output voltage swing extends to within 10 mV of each rail, providing the maximum output dynamic range.

Offset voltage of 800 μV maximum, offset voltage drift of 2 μV/°C, typical input bias currents below 25 pA, and low input voltage noise provide dc precision with source impedances up to 1 GΩ. 1.8 MHz unity gain bandwidth, −93 dB THD at 10 kHz, and 3 V/μs slew rate are provided for a low supply current of 800 μA. The AD820 drives up to 350 pF of direct capacitive load and provides a minimum output current of 15 mA. This allows the amplifier to handle a wide range of load conditions. This combination of ac and dc performance, plus the outstanding load drive capability, results in an exceptionally versatile amplifier for the single-supply user.

The AD820 is available in two performance grades. The A and B grades are rated over the industrial temperature range of −40°C to +85°C. The AD820 is offered in three 8-lead package options: plastic DIP (PDIP), surface mount (SOIC) and (MSOP).


  • Battery-powered precision instrumentation
  • Photodiode preamps
  • Active filters
  • 12-bit to 14-bit data acquisition systems
  • Medical instrumentation
  • Low power references and regulators
  • Data Sheet, Rev. F, 11/08

    Product Lifecycle icon-recommended Production

    At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

    Evaluation Kits (1)

    Tools & Simulations


    LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.


    Models for the following parts are available in LTspice:


    Design Tools

    Analog Filter Wizard

    Use the Analog Filter Wizard to design low-pass, high-pass, or band-pass filters with actual op amps in minutes. As you progress through the design process, you can observe the characteristics of your filter design from ideal specifications to real world circuit behavior. Quickly evaluate the tradeoffs in op amp specifications - including gain-bandwidth, noise, and supply current – to determine the best filter design for your requirements.

    Analog Photodiode Wizard

    Use Photodiode Wizard to design a transimpedance amplifier circuit to interface with a photodiode. Select a photodiode from the library included in the tool, or enter custom photodiode specifications. Quickly observe tradeoffs between Bandwidth, Peaking (Q), and ENOB/SNR. Modify circuit parameters, and immediately see results in plots for pulse response, frequency response, and noise gain.

    Design Resources

    ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.

    Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
    AD820ANZ Material Declaration Reliability Data 8-Lead PDIP
    AD820ARMZ Material Declaration Reliability Data 8-Lead MSOP
    AD820ARMZ-R7 Material Declaration Reliability Data 8-Lead MSOP
    AD820ARMZ-RL Material Declaration Reliability Data 8-Lead MSOP
    AD820ARZ Material Declaration Reliability Data 8-Lead SOIC
    AD820ARZ-REEL Material Declaration Reliability Data 8-Lead SOIC
    AD820ARZ-REEL7 Material Declaration Reliability Data 8-Lead SOIC
    AD820BRZ Material Declaration Reliability Data 8-Lead SOIC
    AD820BRZ-REEL Material Declaration Reliability Data 8-Lead SOIC
    AD820BRZ-REEL7 Material Declaration Reliability Data 8-Lead SOIC
    Wafer Fabrication Data

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    Sample & Buy

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    Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.