Features and Benefits
- Fully specified dual power mode operation
- 4 mA full power mode (145 MHz)
- 1.4 mA low power mode (80 MHz)
- Full power mode
- Low harmonic distortion
- −120 dB THD at 1 kHz
- −110 dB THD at 100 kHz
- Fast settling time
- 18-bit: 100 ns
- 16-bit: 50 ns
- Input voltage noise: 1.6 nV/√Hz, f = 100 kHz
- Low harmonic distortion
- ±100 µV maximum offset voltage from −40°C to +125°C
- Rail-to-rail output
- Wide input common-mode voltage range: −VS to +VS − 1.3 V
- Broad power supplies: 3 V to 10 V
- Adjustable output clamps for ADC input protection
The ADA4945-1 is a low noise, low distortion, fully differential amplifier with two selectable power modes. It is an ideal choice for driving high resolution, high performance SAR and Σ-Δ analog-to-digital converters (ADCs) on 4 mA of quiescent current (full power mode) and can be selected to operate on 1.4 mA of quiescent current (low power mode) to scale the power consumption to the desired performance necessary for the ADC drive application. The adjustable common-mode voltage allows the ADA4945-1 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 ADA4945-1, differential gain configurations are realized with a simple external feedback network of four resistors determining the closed-loop gain of the amplifier. The ADA4945-1 is fabricated using Analog Devices, Inc., proprietary, silicon germanium (SiGe), complementary bipolar process, enabling the device to achieve low levels of distortion with an input voltage noise of only 1.6 nV/√Hz (full power mode).
The low dc offset, dc offset drift, and excellent dynamic performance of the ADA4945-1 makes it well suited for a variety of data acquisition and signal processing applications.
The ADA4945-1 is available in a RoHS-complaint, 3 mm × 3 mm, 16-lead LFCSP. The ADA4945-1 is specified to operate over the –40°C to + 125°C temperature range.
- Low power Σ-Δ, PulSAR®/SAR ADC drivers
- Single-ended to differential conversion
- Differential buffers
- Medical imaging
- Industrial process controls
- Portable electronics
Markets & Technology
- Instrumentation & Measurement
- Aerospace and Defense
Product Lifecycle Pre-Release
This product is new and engineering validation may still be underway. Quantities may be limited and design specifications may change while we ready the product for release to production.
Evaluation Kits (1)
The Analog Devices, Inc., ADA4945-1CP-EBZ evaluation board is used to evaluate the performance of the ADA4945-1 fully differential amplifier. The board can be used as either a standalone evaluation board for general purpose differential amplifier evaluation or as an amplifier mezzanine card for specified ADCs. When configured as a mezzanine card the board is easily mounted atop compatible ADC evaluation boards via the 7-pin Headers J1 and J2. This usage enables quick and easy evaluation of multiple amplifier/ ADC combinations.
The evaluation board can be configured to accept either a single-ended or differential input signal.
The board utilizes several two-pin or three-pin headers to control various features of the ADA4945-1. Headers allow the user to easily set the ADA4945-1 high and low output clamp levels, set the output common-mode voltage, choose high or low power mode, and set the digital ground level.
Optimized power and ground planes ensure low noise and high speed operation. Component placement and power supply bypassing are optimized for maximum circuit flexibility and performance. The evaluation board accepts 0402 or 0603 surface mount technology (SMT) components, 0805 bypass capacitors, and 2.54 mm headers.
Features & Benefits
- Enables quick breadboarding/prototyping
- User defined circuit configuration
- Dual purpose
- Standalone ADA4945-1CP-EBZ evaluation board
- Amplifier mezzanine card for ADC evaluation boards
- Compatible with 10-lead PulSAR evaluation board
Tools & Simulations
Precision ADC Driver Tool - BETA
The Precision ADC Driver Tool is a web application that simulates the performance of precision ADC and driver combinations. Potential issues with driver selection, kickback settling, and distortion are flagged, and design tradeoffs can be quickly evaluated. Simulations and calculations include system noise, distortion, and settling of the ADC input
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.