Overview
Features and Benefits
- Small signal bandwidth: 260 MHz
- Ultralow power 1.25mA
- Extremely low harmonic distortion
- −122 dB THD at 50 kHz
- −96 dB THD at 1 MHz
- Low input voltage noise: 3.9 nV/√Hz
- 0.35 mV maximum offset voltage
- Balanced outputs
- Settling time to 0.1%: 34 ns
- Rail-to-rail output: −VS + 0.1 V to +VS − 0.1 V
- Adjustable output common-mode voltage
- Flexible power supplies: 3 V to 7 V (LFCSP)
- Disable pin to reduce power consumption
Product Details
The ADA4940-1 / ADA4940-2 are low noise, low distortion differential amplifiers with very low power consumption. They are an ideal choice for driving low power, high resolution, high performance SAR and sigma-delta (Σ-Δ) analog-to-digital converters (ADCs) with resolutions up to 18 bits from dc to 1 MHz on only 1.25 mA of quiescent current. The adjustable level of the output common-mode voltage allows the ADA4940-1 / ADA4940-2 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 ADA4940-1 / ADA4940-2, differential gain configurations are easily realized with a simple external feedback network of four resistors determining the closed-loop gain of the amplifier. The ADA4940-1 / ADA4940-2 are fabricated using Analog Devices, Inc., complementary bipolar process, enabling them to achieve very low levels of distortion with an input voltage noise of only 3.9 nV/√Hz. The low dc offset and excellent dynamic performance of the ADA4940-1 / ADA4940-2 make them well suited for a variety of data acquisition and signal processing applications.
The ADA4940-1 is available in a Pb-free, 3 mm × 3 mm, 16-lead LFCSP. The ADA4940-2 is available in a Pb-free, 4 mm × 4 mm, 24-lead LFCSP. The pinout is optimized to facilitate printed circuit board (PCB) layout and minimize distortion. The ADA4940-1 / ADA4940-2 are specified to operate over the −40°C to +125°C temperature range.
Applications
- Low power ADC drivers
- Single-ended-to-differential converters
- Differential buffers
- Line drivers
- Medical Imaging
- Industrial Process Control
- Portable Electronics
Product Categories
Markets and Technologies
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)
Documentation & Resources
-
SAR ADC & Driver Quick-Match Guide9/13/2013
-
Driving Miss ADC8/1/2012
-
Dual Op Amps and Double Agents7/1/2012
-
Fast Reacting, Optical Encoder Feedback System for Miniature Motor Driven Applications4/1/2020 Analog Dialogue
-
RF-to-Bits Solution Offers Precise Phase and Magnitude Data for Material Analysis10/1/2014 Analog Dialogue
Tools & Simulations
LTspice
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
ADA4940
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
SPICE Model
CIR
ADA4940 SPICE Macro Model
4.14 K
Design Tool
ADI DiffAmpCalc™
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.
Reference Designs (2)
Design Resources
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.View our quality and reliability program and certifications for more information.
| Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
|---|---|---|---|---|
| ADA4940-2ACPZ-R2 | Material Declaration | Reliability Data | 24-Lead LFCSP (4mm x 4mm w/ EP) | |
| ADA4940-2ACPZ-R7 | Material Declaration | Reliability Data | 24-Lead LFCSP (4mm x 4mm w/ EP) | |
| ADA4940-2ACPZ-RL | Material Declaration | Reliability Data | 24-Lead LFCSP (4mm x 4mm w/ EP) | |
| Wafer Fabrication Data |
PCN-PDN Information
Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.
Support & Discussions
ADA4940-2 Discussions
recommend full differential ADC driver for ad7380-4
20 week(s) ago in Differential Amplifiers
Sample & Buy
Ordering FAQs
See our Ordering FAQs for answers to questions about online orders, payment options and more.
Buy Now Pricing
(**) Displayed Buy Now Price and Price Range is based on small quantity orders.
List Pricing
(*)The 1Ku 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. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Lead Times
Please see the latest communication from our CCO regarding lead times.
Sampling
A Sample link will be shown above, next to the part, only for parts that are included in our sample program. Selecting the Sample button will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.
Evaluation Boards
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.