Low Power, 24-Bit, 31.25 kSPS, Sigma-Delta ADC with True Rail-to-Rail Buffers

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Product Details

TThe AD7172-2 is an intelligent, low noise, low power, multiplexed, Σ-Δ analog-to-digital converter (ADC) with 2- or 4-channel (fully differential/single-ended) inputs for low bandwidth signals. The AD7172-2 has a maximum channel scan rate of 6.21 kSPS (161 µs) for fully settled data. The output data rates range from 1.25 SPS to 31.25 kSPS.

The AD7172-2 integrates key analog and digital signal conditioning blocks to allow users to configure an individual setup for each analog input channel in use via the SPI. Integrated true rail-to-rail buffers on the analog inputs and external reference inputs provide easy to drive high impedance inputs. The precision 2.5 V low drift (2 ppm/°C) band gap internal reference (with an output reference buffer) adds embedded functionality to reduce the external component count.

The digital filter allows simultaneous 50 Hz and 60 Hz rejection at a 27.27 SPS output data rate. The user can switch between different filter options according to the demands of each channel in the application, with further digital processing functions such as offset and gain calibration registers, which are also configurable on a per channel basis. General-purpose inputs/outputs (GPIOs) control external multiplexers synchronous to the ADC conversion timing.

The specified operating temperature range is −40°C to +105°C. The AD7172-2 is in a 24-lead TSSOP package.


  • Process control: PLC/DCS modules
    - Temperature and pressure measurement
  • Medical and scientific multichannel instrumentation
  • Chromatography

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.

Alternative Parts

Evaluation Kits


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EVAL-AD7172-2 Circuit Diagram

Product Details

The EVAL-AD7172-2SDZ evaluation kit features the AD7172-2, a low power, 24-bit, 31.25 kSPS, Σ-Δ analog-to-digital converter (ADC) with true rail-to-rail buffers, on-board power supply regulation, and an external amplifier section for amplifier evaluation. A 7 V to 9 V ac-to-dc adapter is regulated to 5 V and 3.3 V; this supplies the AD7172-2 and support components. The EVAL-AD7172-2SDZ connects to a USB port via the SDP on the EVAL-SDP-CB1Z controller board.

The EVAL-AD7172-2SDZ evaluation software fully configures the AD7172-2 device functionality via a user accessible register interface and provides dc time domain analysis in the form of waveform graphs, histograms, and associated noise analysis for ADC performance evaluation.

Full details about the device are available in the AD7172-2 data sheet, which should be consulted when using the EVAL-AD7172-2SDZ.


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Software & Systems Requirements


Tools & Simulations

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Virtual Eval - BETA

Virtual Eval is a web application to assist designers in product evaluation of ADCs and DACs. Using detailed models on Analog’s servers, Virtual Eval simulates crucial part performance characteristics within seconds. Configure operating conditions such as input tones and external jitter, as well as device features like gain or digital down-conversion. Performance characteristics include noise, distortion, and resolution, FFTs, timing diagrams, frequency response plots, and more.


Product Recommendations

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AD7172-2 Companion Parts

Recommended Digital Isolators

  • For SPI Interface, lowest power, 2.5 kVrms isolation , we recommend the ADUM1401 .
  • For SPI Interface, smallest package, low voltage I/O (1.8 V to 5.5 V) , we recommend the ADUM3481 .
  • For SPI Interface, low power, 5.0 kVrms isolation , we recommend the ADUM4401 .
  • For SPI Interface, enhanced system-level ESD performance, 2.5 kVrms isolation , we recommend the ADUM3401 .

Recommended Power Solutions

  • For voltage conversion which can double or invert voltages to help with power supply rail generation , we recommend the ADM660 .
  • For a low noise, high power supply rejection, positive supply voltage LDO , we recommend the ADP7118 .
  • For a low noise, high power supply rejection, negative supply voltage LDO , we recommend the ADP7182 .

Recommended Driver Amplifiers

  • For a single supply, ultralow noise, zero drift, rail to rail input and output amplifier , we recommend the ADA4528-2 .
  • For a high voltage, ultralow noise, zero drift, rail to rail output amplfier , we recommend the ADA4522-2 .

Recommended External Multiplexers

  • For low Ron, 4:1 channel multiplexer , we recommend the ADG1404 .
  • For low Ron with four differential inputs , we recommend the ADG1409 .

Recommended External Voltage References

  • For the family of low noise, low drift and high accuracy references , we recommend the ADR445 or the ADR4550 .

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.

AD7172-2 Material Declaration
PCN-PDN Information Quality And Reliability Symbols and Footprints



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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.