Features and Benefits
- Broad power supply range: 3 V to 10 V
- Wide input common-mode voltage range: −VS to +VS − 1.3 V
- Rail-to-rail output
- 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
- −133 dBc HD2 and −140 dBc HD3 at 1 kHz
- −133 dBc HD2 and −116 dBc HD3 at 100 kHz
- Fast settling time
- 18-bit: 100 ns
- 16-bit: 50 ns
- Input voltage noise: 1.8 nV/√Hz, f = 100 kHz
- ±115 μV maximum offset voltage from −40°C to +125°C
- Adjustable output clamps for ADC input protection
The ADA4945-1 is a low noise, low distortion, fully differential amplifier with two selectable power modes. The device operates over a broad power supply range of 3 V to 10 V. 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 device is an ideal choice for driving high resolution, high performance successive approximation register (SAR) and Σ-Δ analog-to-digital converters (ADCs) on 4 mA of quiescent current (full power mode). The device can also 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 an 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 achieved 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 1.8 nV/√Hz (full power mode).
The ADA4945-1 is available in a RoHS-complaint, 3 mm × 3 mm, 16-lead LFCSP. The ADA4945-1 is specified to operate from −40°C to +125°C.
- Low power Σ-Δ, PulSAR®, and SAR ADC drivers
- Single-ended to differential converters
- Differential buffers
- Medical imaging
- Process control
- Portable electronics
Markets & Technology
- Instrumentation & Measurement
- Aerospace and Defense
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
The Analog Devices, Inc., ADA4945-1CP-EBZ evaluation board allows the user to evaluate the performance of the ADA4945-1 fully differential amplifier. The ADA4945-1CP-EBZ evaluation board can be configured to accept either a single-ended or differential input signal.
The ADA4945-1CP-EBZ evaluation board uses several 2-pin and 3-pin headers to control various features of the ADA4945-1. Apply the proper jumpers to set the ADA4945-1 high and low output clamp levels, set the ADA4945-1 output common-mode voltage, choose high or low power mode for the ADA4945-1, and set the ADA4945-1 digital ground level.
Optimized power and ground planes ensure low noise and high speed operation. Component placement and power supply bypassing provide maximum circuit flexibility and performance. The ADA4945-1CP-EBZ evaluation board accepts 0402 surface mount technology (SMT) components, 0805 bypass capacitors, and 2.54 mm headers.
Input and output signals are brought to and from the board via 50 Ω, side launch Subminiature Version A (SMA) connectors.
Full specifications on the ADA4945-1 are available in the ADA4945-1 data sheet. Consult the data sheet in conjunction with this user guide when working with the ADA4945-1CP-EBZ evaluation board.
Features & Benefits
- Enables quick breadboarding and prototyping
- User defined circuit configuration
Tools & Simulations
Precision ADC Driver Tool
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.