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ADA4939-1:  Ultralow Distortion Differential ADC Driver

Product Details

The ADA4939 is a low noise, ultralow distortion, high speed differential amplifier. It is an ideal choice for driving high performance ADCs with resolutions up to 16 bits from dc to 100 MHz. The output common-mode voltage is user adjustable by means of an internal common-mode feedback loop, allowing the ADA4939 output to match the input of the ADC. The internal feedback loop also provides exceptional output balance as well as suppression of even-order harmonic distortion products.

With the ADA4939, differential gain configurations are easily realized with a simple external feedback network of four resistors that determine the closed-loop gain of the amplifier.

The ADA4939 is fabricated using Analog Devices, Inc., proprietary silicon-germanium (SiGe), complementary bipolar process, enabling it to achieve very low levels of distortion with an input voltage noise of only 2.3 nV/√Hz. The low dc offset and excellent dynamic performance of the ADA4939 make it well suited for a wide variety of data acquisition and signal processing applications.

The ADA4939 is available in a Pb-free, 3 mm × 3 mm 16-lead LFCSP (ADA4939-1, single) or a Pb-free, 4 mm × 4 mm 24-lead LFCSP (ADA4939-2, dual). The pinout has been optimized to facilitate PCB layout and minimize distortion. The ADA4939-1 and the ADA4939-2 are specified to operate over the −40°C to +105°C temperature range; both operate on supplies between 3.3 V and 5 V.


  • ADC drivers
  • Single-ended-to-differential converters
  • IF and baseband gain blocks
  • Differential buffers
  • Line drivers
  • Data Sheet, Rev. 0, 5/08


    • Extremely low harmonic distortion
      −102 dBc HD2 @ 10 MHz
      −83 dBc HD2 @ 70 MHz
      −77 dBc HD2 @ 100 MHz
      −101 dBc HD3 @ 10 MHz
      −97 dBc HD3 @ 70 MHz
      −91 dBc HD3 @ 100 MHz
    • Low input voltage noise: 2.3 nV/√Hz
    • High speed
      −3 dB bandwidth of 1.4 GHz, G = 2
      Slew rate: 6800 V/μs, 25% to 75%
      Fast overdrive recovery of <1 ns
    • ±0.5 mV typical offset voltage
    • Externally adjustable gain
    • Stable for differential gains ≥2
    • Differential-to-differential or single-ended-to-differential operation
    • Adjustable output common-mode voltage
    • Single-supply operation: 3.3 V to 5 V

    Functional Block Diagram for ADA4939-1


    Title Content Type File Type
    ADA4939-1/ADA4939-2: Ultralow Distortion Differential ADC Driver Data Sheet (Rev 0, 05/2008) (pdf, 622 kB) Data Sheets PDF
    AN-1026: High Speed Differential ADC Driver Design Considerations  (pdf, 355 kB) Application Notes PDF
    AN-0990: Terminating a Differential Amplifier in Single-Ended Input Applications  (pdf, 181 kB) Application Notes PDF
    AN-0992: Active Filter Evaluation Board for Differential Amplifiers  (pdf, 85 kB) Application Notes PDF
    AN-282: Fundamentals of Sampled Data Systems  (pdf, 2131 kB) Application Notes PDF
    AN-649: Using the Analog Devices Active Filter Design Tool  (pdf, 5301 kB) Application Notes PDF
    AN-584: Using the AD813X Differential Amplifier  (pdf, 174 kB)
    The AD813x differs from conventional op amps by the external presence of an additional input and output. The additional input, VOGM, controls the output common mode voltage.
    Application Notes PDF
    AN-589: Ways to Optimize the Performance of a Difference Amplifier  (pdf, 115 kB)
    This Application Note presents several ways to build and optimize the performance of a discrete difference amplifier. It also recommends amplifiers that will make the overall solution cost/performance competitive with monolithic instrument amplifiers.
    Application Notes PDF
    MT-218: Multiple Feedback Band-Pass Design Example  (pdf, 0) Tutorials PDF
    MT-076: Differential Driver Analysis  (pdf, 95 kB) Tutorials PDF
    MT-075: Differential Drivers for High Speed ADCs Overview  (pdf, 183 kB) Tutorials PDF
    A Stress-Free Method for Choosing High-Speed Op Amps
    A decision-tree approach to making the critical decision about high-speed op amp selection, including a look at some helpful tools.
    Webcasts WEBCAST
    UG-132: Evaluation Board User Guide for the ADA492x-1 and ADA493x-1 Family of Differential Amplifiers  (pdf, 226 kB)
    Differential Amplifier Evaluation Board for Single 16-lead 3 mm × 3 mm LFCSP Packages
    User Guides PDF
    "Rules of the Road" for High-Speed Differential ADC Drivers
    (Analog Dialogue, Vol. 43, No. 5, 2009)
    Analog Dialogue HTML
    RF Source Booklet  (PDF, 4353 kB)
    RF IC Product Overview - Version P (02/2014)
    Overview PDF
    RAQs index Rarely Asked Questions HTML
    Glossary of EE Terms Glossary HTML

    Design Tools,Models,Drivers & Software

    Title Content Type File Type
    ADI DiffAmpCalc™
    ADI's new ADI DiffAmpCalc™ is a free, downloadable calculator for designing differential amplifier circuits. The tool is easy to use and features an interactive user interface to quickly get you up and running.
    ADIsim Design/Simulation Tools HTML
    ADA4939 SPICE Macro Model  (cir) SPICE Models CIR

    Evaluation Kits & Symbols & Footprints

    Evaluation Boards & KitsView the Evaluation Boards and Kits page for documentation and purchasing

    Symbols and Footprints— Analog Devices offers Symbols & Footprints which are compatible with a large set of today’s CAD systems for broader and easier support.

    SampleSample & Buy

    Price, packaging, availability

    ADA4939-1 Model Options
    Model Package Pins Temp.
    Price*(100-499) Price*1000 pcs RoHS View PCN/ PDN Check Inventory/
    ADA4939-1YCPZ-R2 Status: Production LFCSP:LEADFRM CHIP SCALE 16 Ind Reel, 250 $4.70 $4.70 Y  Material Info PCN Purchase
    ADA4939-1YCPZ-R7 Status: Production LFCSP:LEADFRM CHIP SCALE 16 Ind Reel, 1500 - $3.79 Y  Material Info PCN Purchase Sample
    ADA4939-1YCPZ-RL Status: Production LFCSP:LEADFRM CHIP SCALE 16 Ind Reel, 5000 - $3.79 Y  Material Info PCN Purchase
    Price Table Help

    The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

    ADA4939-1 Evaluation Board
    Model Description Price RoHS View PCN/ PDN Check Inventory/
    ADA4939-1YCP-EBZ Status: Production 16-Lead LFCSP Bare Evaluation Board $18.25 Yes -
    ADA4939-1YCPZ-R7 Status: Production 16-Lead LFCSP - Yes -

    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.

    Check Inventory & Purchase

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