ADA4939-2 Ultralow Distortion Differential ADC Driver

The ADA4939-1 / ADA4939-2 are low noise, ultralow distortion, high speed differential amplifiers. They are 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 ADA4939-1 / ADA4939-2 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 ADA4939-1 / ADA4939-2, 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 ADA4939-1 / ADA4939-2 are fabricated using Analog Devices, Inc., proprietary silicon-germanium (SiGe), complementary bipolar process, enabling them 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 ADA4939-1 / ADA4939-2 make them well suited for a wide variety of data acquisition and signal processing applications.

The ADA4939-1 (single) is available in a 3 mm × 3 mm, 16-lead LFCSP, and the ADA4939-2 (dual) is available in a 4 mm × 4 mm, 24-lead LFCSP. The pinouts are optimized to facilitate printed circuit board (PCB) layout and minimize distortion. The ADA4939-1/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.

Applications

Features and Benefits
  • Extremely low harmonic distortion
    • −102 dBc HD2 at 10 MHz
    • −83 dBc HD2 at 70 MHz
    • −77 dBc HD2 at 100 MHz
    • −101 dBc HD3 at 10 MHz
    • −97 dBc HD3 at 70 MHz
    • −91 dBc HD3 at 100 MHz
  • −102 dBc HD2 at 10 MHz
  • −83 dBc HD2 at 70 MHz
  • −77 dBc HD2 at 100 MHz
  • −101 dBc HD3 at 10 MHz
  • −97 dBc HD3 at 70 MHz
  • −91 dBc HD3 at 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
  • −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
  • Amplifiers
    SPICE Models
    Data Sheets
    Documentnote
    ADA4939-1/ADA4939-2: Ultralow Distortion, Differential ADC Driver Data Sheet (Rev. A)PDF 583.48 K
    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-282: Fundamentals of Sampled Data SystemsPDF 2131 kB
    AN-0990: Terminating a Differential Amplifier in Single-Ended Input Applications (Rev. 0)PDF 181 kB
    AN-0992: Active Filter Evaluation Board for Differential Amplifiers (Rev. 0)PDF 85 kB
    AN-1026: High Speed Differential ADC Driver Design Considerations (Rev. A)PDF 355 kB
    AN-649: Using the Analog Devices Active Filter Design Tool (Rev. 0)PDF 5.3 M
    AN-584: Using the AD813X Differential Amplifier (Rev. 0)PDF 174 kB
    AN-589: Ways to Optimize the Performance of a Difference Amplifier (Rev. B)PDF 115 kB
    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
    ADA4939-2YCPZ-R2 Production24 ld LFCSP (4x4x.75mm w/2.10mm EP) REEL 250-40 to 105C7.697.69Y
    ADA4939-2YCPZ-R7 Production24 ld LFCSP (4x4x.75mm w/2.10mm EP) REEL 1500-40 to 105C05.69Y
    ADA4939-2YCPZ-RL Production24 ld LFCSP (4x4x.75mm w/2.10mm EP) REEL 5000-40 to 105C05.69Y
    Evaluation Boards
    Part NumberDescriptionPriceRoHS
    EVAL-FDA-2CPZ-24Evaluation Bare Board for 24 Lead LFCSP18.25Y
    Reference Materials
    ADA4939-1/ADA4939-2: Ultralow Distortion, Differential ADC Driver Data Sheet (Rev. A) ada4939-1
    ADA4939-1/ADA4939-2: 超低失真差分 ADC驱动器 (Rev. 0) ada4939-1
    ADA4939 SPICE Macro Model ada4939-1
    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-282: Fundamentals of Sampled Data Systems ad1674
    AN-0990: Terminating a Differential Amplifier in Single-Ended Input Applications (Rev. 0) ad8138
    AN-0992: Active Filter Evaluation Board for Differential Amplifiers (Rev. 0) ad8138
    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
    AN-589: 差动放大器性能优化方法 (Rev. 0) ad8350
    AN-584: AD813x的运用 (Rev. 0) ad8138
    AN-0990: 在单端输入应用中连接差分放大器 (Rev. 0) ad8138
    AN-0992: 用于差分放大器的有源滤波器评估板 (Rev. 0) ad8138
    AN-282: 采样数据系统基本原理[中文版] (Rev. A) ad75019
    AN-649: Using the Analog Devices Active Filter Design Tool (Rev. 0) ad8350
    AN-584: Using the AD813X Differential Amplifier (Rev. 0) ad8138
    AN-589: Ways to Optimize the Performance of a Difference Amplifier (Rev. B) ad8350
    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
    MT-076:差分驱动器分析 ad8138
    MT-075: Differential Drivers for High Speed ADCs Overview ad6672