AD8421

3 nV /√Hz, Low Power Instrumentation Amplifier
Manufactured by:

Product Details

The AD8421 is a low cost, low power, extremely low noise, ultra-low bias current, high speed instrumentation amplifier which is ideally suited for a broad spectrum of signal conditioning and data acquisition applications. This breakthrough product features the highest CMRR available, allowing it to extract low-level signals in the presence of high-frequency common mode noise over a wide temperature range.

The 10 MHz bandwidth, 35 V/µs slew rate, and 0.7 µs settling time to 0.01% (G = 1) allow the AD8421 to amplify high-speed signals and excel in applications that require high channel-count multiplexed systems. Even at high gain, the current feedback architecture preserves this performance, for example, at G = 100, the bandwidth is 2 MHz and the settling time is 0.6 µs. The AD8421 has excellent distortion performance, allowing use in demanding applications such as vibration analysis.

The AD8421 delivers industry-leading 3 nV/√Hz input voltage noise and 200 fA/√Hz current noise with only 2 mA quiescent current, making it an ideal choice for measuring low-level signals. For applications with significant source impedance, the AD8421 employs novel process technology and innovative design techniques to provide groundbreaking noise performance limited only by the sensor.

The AD8421 uses a unique input protection method to give it robust inputs while still maintaining very low noise. This input protection allows voltages 40 V from the opposite supply rail without damage.

A single resistor sets gains between 1 and 10,000. The reference pin can be used to apply a precise offset to the output voltage.

The AD8421 performance is specified from −40°C to +85°C and has typical performance curves to 125°C. It is available in MSOP and SOIC packages.

Applications

  • Medical instrumentation
  • Precision data acquisition
  • Microphone preamplification
  • Vibration analysis
  • Multiplexed input applications
  • ADC driver

Product Lifecycle

checked 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

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Product Details

This page contains evaluation board documentation and ordering guide information for evaluating AD8421.

Tools & Simulations

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SPICE Models

Design Resources

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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.

AD8421 Material Declaration
PCN-PDN Information Quality And Reliability Symbols and Footprints

Reviews

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Overview

11 Reviews
10 out of 11 (90%) customers recommend this product.
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Most Helpful Review

by Anonymous
Instrumentation amplifier with higher usable frequency (3 to 5 MHz would be nice). AD8421 is good to 1 MHz but degrades too fast after that.

Most Recent Review

by linear, TI
This product has small foot print compare to other similar instrument amplifiers. Also has sufficient CMRR to use for special application with special filters I use. IT has a gain range using simple external resistor.

All Reviews

by linear, TI, 13 Aug 14
This product has a suitable diemntion need for my aplication
This product has small foot print compare to other similar instrument amplifiers. Also has sufficient CMRR to use for special application with special filters I use. IT has a gain range using simple external resistor.
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by agnelors, 27 May 14
Excellent noise performance
I used the chip at the input of a magnetic induction device with signals smaller than 50microV. Due to the noise level of the chip, I achieved my goal.
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by Valerio GIampa, 8 May 14
OpAmp High Speed
Good Performance, ood functionality, good features, good power consumption under the declared value.
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by Anonymous, 6 May 14
AD8421 for high impedance sources
The AD8421 is very simple to implement and provides a good amplification chain for high frequency high impedance sources.
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by Test and Measurement Eng., 18 Feb 14
Good Instr. AMplifier
Good amplifier, Input and output swing could be better.
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by arcover1024, 7 Nov 13
Very good for high gain
The AD8421 will work very well with a gain greater than 20. Below this level, the elevated gain at around a few MHz (as shown in the datasheet in Figure 21) might lead to signal distortion, depending on the intended application. Anyway, noise performance is great.
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by Anonymous, 15 Oct 13
This IC is a great product
I like this product because of its simple structure as well as excellent performance.
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by theruffz, 13 Aug 13
sweet
very good thanks AD my prototype doesn't works without yours instrumentational amplifers!!!
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by Joul, 8 Aug 13
good performance
easy to use instrumentation amplifier with good performance
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by Mario, 1 Jun 13
SPI too slow
Hi There, it would be great if this DAC had a faster SPI clock than 25MHz... Otherwise it's an awesome DAC! Cheers! Mario
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by Anonymous, 16 Mar 13
This product perfoms very well and reduces component count vs discrete solution.
Instrumentation amplifier with higher usable frequency (3 to 5 MHz would be nice). AD8421 is good to 1 MHz but degrades too fast after that.
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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.


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Evaluation Boards Pricing displayed is based on 1-piece.
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.