ADA4940-2 Ultralow Power, Low Distortion ADC Driver

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
  • Amplifiers
    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
    User Guides
    Documentnote
    UG-018: Evaluation Board for Dual High Speed Differential AmplifiersPDF 314 kB
    Order Information
    Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
    ADA4940-2ACPZ-R2 Production24 ld LFCSP 4x4mm (2.5EP) REEL 250-40 to 125C3.93.9Y
    ADA4940-2ACPZ-R7 Production24 ld LFCSP 4x4mm (2.5EP) REEL 1500-40 to 125C3.152.59Y
    ADA4940-2ACPZ-RL Production24 ld LFCSP 4x4mm (2.5EP) REEL 5000-40 to 125C3.152.59Y
    Evaluation Boards
    Part NumberDescriptionPriceRoHS
    EVAL-FDA-2CPZ-24Evaluation Bare Board for 24 Lead 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
    CN0374 设计与集成文件 ada4940-2
    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
    UG-018: Evaluation Board for Dual High Speed Differential Amplifiers ada4937-2
    MT-218: 多反馈带通滤波器设计示例 ad8138
    SAR ADC & Driver Quick-Match Guide ad7476
    CN0374:RF至位解决方案可提供6 GHz信号的精密相位和幅度数据 ada4940-2
    CN0237: 超低功耗、18位、差分PulSAR ADC驱动 ada4940-1