High Temperature, Low Drift, Micropower, 2.5V Reference

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Product Details

The ADR225 is a precision 2.5 V band gap voltage reference specified for a high temperature operation of 175°C and 210°C. It uses a micropower core topology and laser trimming of highly stable, thin film resistors to achieve a temperature coefficient of 30 ppm/°C (maximum) up to 175°C and an initial accuracy of 0.4% (±10 mV maximum). A maximum operating current of 50 µA and a low dropout voltage allow the ADR225 to function very well in battery-powered equipment.

The ADR225 voltage reference is offered in an 8-lead SOIC package with an operating temperature range of −40°C to +175°C.

It is also available in an 8-lead ceramic flat pack (FLATPACK) with an operating temperature range of −40°C to +210°C. Both devices are designed for robustness at extreme temperatures and are qualified for 1000 hours of operation at the maximum temperature rating.

The ADR225 is a member of a growing series of high temperature qualified products offered by Analog Devices, Inc. For a complete selection table of the available high temperature products, see the high temperature product list and qualification data available at


  • Down-hole drilling and instrumentation
  • Avionics
  • Heavy industrial
  • High temperature environments

Product Lifecycle

icon-recommended 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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EV-HT-200CDAQ1 Circuit Diagram

EV-HT-200CDAQ1 Photo

Product Details

EV-HT-200CDAQ1 builds on the CN0365 analog front end reference design from with the goal of providing a foundation for a high temperature, low power microcontroller-based data acquisition and control solution that meets the requirements for many downhole instrumentation and other high temperature applications. Based upon the AD7981 analog-to-digital SAR converter, this reference design demonstrates a full featured system with two high speed simultaneously sampled channels along with 8 additional multiplexed channels suitable for covering the acquisition requirements of a broad range of downhole tools (10 channels total). This analog front end is connected to the VORAGO Technologies VA10800 ARM® Cortex®-M0 based microcontroller via multiple SPI ports. Once acquired, the data can be processed locally or transmitted via a UART or optional RS485 communications interface. Other supporting components on the board, including memory, clock, power and passives are all rated for high temperature operation by their respective suppliers and verified to operate reliably at 200°C or higher. In addition to the hardware, open source firmware is supplied for the project using FreeRTOS with optimized drivers and data acqusition protocol with multiple modes of operation. Open source PC software included allows the users to connect to the board via UART to control acquisition modes, view data, log data and perform signal analysis. This platform is suitable for reference design, rapid prototyping (such as new sensor techniques) and lab testing of high temperature instrumentation systems.

Reference Designs


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CN0365 Circuit Diagram

CN0365 Photo

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.

ADR225 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.