Features and Benefits
- Extremely low harmonic distortion (HD)
- −106 dBc HD2 at 10 MHz
- −82 dBc HD2 at 50 MHz
- −109 dBc HD3 at 10 MHz
- −82 dBc HD3 at 50 MHz
- Low input voltage noise: 2.6 nV/√Hz
- High speed
- −3 dB bandwidth of 1000 MHz, G = +1
- Slew rate: 4700 V/μs
- 0.1 dB gain flatness to 150 MHz
- Fast overdrive recovery of 4 ns
- 1 mV typical offset voltage
- Externally adjustable gain
- Differential-to-differential or single-ended-to-differential operation
- Adjustable output common-mode voltage
- Wide supply voltage range: +5 V to ±5 V
- Single or dual amplifier configuration available
The ADA4938-1 / ADA4938-2 are low noise, ultralow distortion, high speed differential amplifiers. It is an ideal choice for driving high performance ADCs with resolutions up to 16 bits from dc to 27 MHz, or up to 12 bits from dc to 74 MHz. The output common-mode voltage is adjustable over a wide range, allowing the ADA4938-1/ADA4938-2 to match the input of the ADC. The internal common-mode feedback loop also provides exceptional output balance as well as suppression of even-order harmonic distortion products.
Full differential and single-ended-to-differential gain configurations are easily realized with the ADA4938-1/ADA4938-2. A simple external feedback network of four resistors determines the closed-loop gain of the amplifier.
The ADA4938-1 / ADA4938-2 are fabricated using the Analog Devices, Inc., proprietary third generation, high voltage XFCB process, enabling it to achieve very low levels of distortion with an input voltage noise of only 2.6 nV/√Hz. The low dc offset and excellent dynamic performance of the ADA4938-1/ADA4938-2 makes them well-suited for a wide variety of data acquisition and signal processing applications.
The ADA4938-1 (single amplifier) is available in a Pb-free, 3 mm × 3 mm, 16-lead LFCSP. The ADA4938-2 (dual amplifier) is available in a Pb-free, 4 mm × 4 mm, 24-lead LFCSP. The pinouts have been optimized to facilitate layout and minimize distortion. The devices are specified to operate over the extended industrial temperature range of −40°C to +85°C.
- 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 (7)
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.
Product Selection Guide (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.