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
- 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
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.
- ADC drivers
- Single-ended-to-differential converters
- IF and baseband gain blocks
- Differential buffers
- Line drivers
Product Lifecycle 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)
The Universal Differential Amplifier Evaluation Boards can be used to evaluate single, high speed, fully differential amplifiers. The evaluation boards are bare boards that enable users to quickly prototype a variety of differential or single-ended circuits, which minimizes risk and reduces time to market. These boards are all RoHs Compliant. See references below on what board to order by lead count and package.
Application Notes (6)
Tools & Simulations
ADIsimPE, which is powered by SIMetrix/SIMPLIS, is a circuit simulation suite optimized for the design and development of analog and mixed signal circuits. SIMetrix mode is ideal for the simulation of general non-switching circuits. It provides full Pspice compatibility for use with industry-standard SPICE models. SIMPLIS (SIMulation Piecewise-Linear System) mode simulates the operation of switching circuits with vastly improved robustness, speed, and accuracy compared to standard SPICE. It is particularly useful for switching power supply, PLLs, and ADC/DAC applications.
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.
Analog Dialogue (1)
Rarely Asked Questions (1)
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.
Sample & Buy
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.