ADA4940-1 Ultralow Power, Low Distortion ADC Driver

With the ADA4940-1 / ADA4940-2, differential gain configurations are easily realized with a simple external feedback network of four resistors determining the closed-loop gain of the amplifier. The ADA4940-1 / ADA4940-2 are fabricated using Analog Devices, Inc., complementary bipolar process, enabling them to achieve very low levels of distortion with an input voltage noise of only 3.9 nV/√Hz. The low dc offset and excellent dynamic performance of the ADA4940-1 / ADA4940-2 make them well suited for a variety of data acquisition and signal processing applications. The ADA4940-1 is available in a Pb-free, 3 mm × 3 mm, 16-lead LFCSP. The ADA4940-2 is available in a Pb-free, 4 mm × 4 mm, 24-lead LFCSP. The pinout is optimized to facilitate printed circuit board (PCB) layout and minimize distortion. The ADA4940-1 / ADA4940-2 are specified to operate over the −40°C to +125°C temperature range. Applications Low power ADC drivers Single-ended-to-differential converters Differential buffers Line drivers Medical Imaging Industrial Process Control Portable Electronics

The ADA4940-1 / ADA4940-2 are low noise, low distortion differential amplifiers with very low power consumption. They are an ideal choice for driving low power, high resolution, high performance SAR and sigma-delta (Σ-Δ) analog-to-digital converters (ADCs) with resolutions up to 18 bits from dc to 1 MHz on only 1.25 mA of quiescent current. The adjustable level of the output common-mode voltage allows the ADA4940-1/ ADA4940-2 to match the input common-mode voltage of multiple ADCs. The internal common-mode feedback loop provides exceptional output balance, as well as suppression of even-order harmonic distortion products.

With the ADA4940-1 / ADA4940-2, differential gain configurations are easily realized with a simple external feedback network of four resistors determining the closed-loop gain of the amplifier. The ADA4940-1 / ADA4940-2 are fabricated using Analog Devices, Inc., complementary bipolar process, enabling them to achieve very low levels of distortion with an input voltage noise of only 3.9 nV/√Hz. The low dc offset and excellent dynamic performance of the ADA4940-1 / ADA4940-2 make them well suited for a variety of data acquisition and signal processing applications.

The ADA4940-1 is available in a Pb-free, 3 mm × 3 mm, 16-lead LFCSP. The ADA4940-2 is available in a Pb-free, 4 mm × 4 mm, 24-lead LFCSP. The pinout is optimized to facilitate printed circuit board (PCB) layout and minimize distortion. The ADA4940-1 / ADA4940-2 are specified to operate over the −40°C to +125°C temperature range.

Applications
  • Low power ADC drivers
  • Single-ended-to-differential converters
  • Differential buffers
  • Line drivers
  • Medical Imaging
  • Industrial Process Control
  • Portable Electronics
Features and Benefits
  • Small signal bandwidth: 260 MHz
  • Ultralow power 1.25mA
  • Extremely low harmonic distortion
    • −122 dB THD at 50 kHz
    • −96 dB THD at 1 MHz
  • −122 dB THD at 50 kHz
  • −96 dB THD at 1 MHz
  • Low input voltage noise: 3.9 nV/√Hz
  • 0.35 mV maximum offset voltage
  • Balanced outputs
  • Settling time to 0.1%: 34 ns
  • Rail-to-rail output: −VS + 0.1 V to +VS − 0.1 V
  • Adjustable output common-mode voltage
  • Flexible power supplies: 3 V to 7 V (LFCSP)
  • Disable pin to reduce power consumption
  • Available in LFCSP and SOIC packages
  • Amplifiers
    Aerospace and Defense
    • Solutions
    SPICE Models
    Reference Designs
    Data Sheets
    Documentnote
    ADA4940-1/ADA4940-2: Ultralow Power, Low Distortion, Fully Differential ADC Drivers Data Sheet (Rev. D)PDF 1.04 M
    Application Notes
    Documentnote
    AN-1363: Meeting Biasing Requirements of Externally Biased RF/Microwave Amplifiers with Active Bias Controllers (Rev. 0)PDF 804.11 K
    AN-1026: High Speed Differential ADC Driver Design Considerations (Rev. A)PDF 355 kB
    User Guides
    Documentnote
    UG-889: Evaluation Board for Single Differential Amplifiers Offered in 16-Lead LFCSP Packages (Rev. A)PDF 200.15 K
    UG-474: Evaluation Board for Differential Amplifiers Offered in 8-Lead SOIC PackagesPDF 263 kB
    Order Information
    Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
    ADA4940-1ACPZ-R2 Production16 ld LFCSP (3x3mm, 1.3mm exposed pad)REEL 250-40 to 125C2.362.36Y
    ADA4940-1ACPZ-R7 Production16 ld LFCSP (3x3mm, 1.3mm exposed pad)REEL 1500-40 to 125C1.911.59Y
    ADA4940-1ACPZ-RL Production16 ld LFCSP (3x3mm, 1.3mm exposed pad)REEL 5000-40 to 125C1.911.59Y
    ADA4940-1ARZ Production8 ld SOICOTH 98-40 to 125C1.911.59Y
    ADA4940-1ARZ-R7 Production8 ld SOICREEL 1000-40 to 125C01.59Y
    ADA4940-1ARZ-RL Production8 ld SOICREEL 2500-40 to 125C01.59Y
    Evaluation Boards
    Part NumberDescriptionPriceRoHS
    EVAL-FDA-1CPZ-16Evaluation Bare Board for 16 Lead LFCSP18.25Y
    EVAL-FDA-1RMZ-8Evaluation Bare Board for 8 Lead MSOP18.25Y
    EVAL-FDA-1RZ-8Evaluation Bare Board for 8 Lead SOIC18.25Y
    FDA-FILTER-CPZEvaluation Board Filter for LFCSP18.25Y
    Reference Materials
    ADA4940-1/ADA4940-2: Ultralow Power, Low Distortion, Fully Differential ADC Drivers Data Sheet (Rev. D) ada4940-1
    ADA4940-1/ADA4940-2:超低功耗、低失真全差分ADC驱动器 (Rev. B) ada4940-1
    ADA4940 SPICE Macro Model ada4940-1
    CN0237 Design & Integration Files ada4940-1
    AN-1363: 利用有源偏置控制器满足外部偏置射频/微波放大器的偏置要求 (Rev. 0) hmc8120
    AN-1363: Meeting Biasing Requirements of Externally Biased RF/Microwave Amplifiers with Active Bias Controllers (Rev. 0) hmc8120
    AN-1026: High Speed Differential ADC Driver Design Considerations (Rev. A) ad8351
    AN-1026: 高速差分ADC驱动器设计考虑[中文版] (Rev. 0) ad8351
    UG-889: Evaluation Board for Single Differential Amplifiers Offered in 16-Lead LFCSP Packages (Rev. A) ada4937-1
    UG-474: Evaluation Board for Differential Amplifiers Offered in 8-Lead SOIC Packages ad8138
    MT-218: 多反馈带通滤波器设计示例 ad8138
    SAR ADC & Driver Quick-Match Guide ad7476
    CN0237: 超低功耗、18位、差分PulSAR ADC驱动 ada4940-1
    How High Performance Modular Instruments Enable Greater Applications and... ad7768
    Exploring Different SAR ADC Analog Input Architectures ad7982
    Low Power Precision Data Acquisition Signal Chain for Space Constrained... ad7982