Zero Drift, Digitally Programmable Instrumentation Amplifier
The AD8231 is a low drift, rail-to-rail, instrumentation amplifier with software-programmable gains of 1, 2, 4, 8, 16, 32, 64, or 128. The gains are programmed via digital logic or pin strapping.
The AD8231 is ideal for applications that require precision performance over a wide temperature range, such as industrial temperature sensing and data logging. Because the gain setting resistors are internal, maximum gain drift is only 10 ppm/°C for gains of 1 to 32. Because of the auto-zero input stage, maximum input offset is 15 μV and maximum input offset drift is just 50 nV/°C. CMRR is 80 dB for G = 1, increasing to 110 dB at higher gains.
The AD8231 also includes an uncommitted op amp that can be used for additional gain, differential signal driving, or filtering. Like the in-amp, the op amp has an auto-zero architecture, rail-to-rail input, and rail-to-rail output.
The AD8231 includes a shutdown feature that reduces current to a maximum of 1 μA. In shutdown, both amplifiers also have a high output impedance, which allows easy multiplexing of multiple amplifiers without additional switches.
The AD8231 is specified over the extended industrial tempera-ture range of −40°C to +125°C. It is available in a 4 mm × 4 mm 16-lead LFCSP.
- Pressure and strain transducers
- Thermocouples and RTDs
- Programmable instrumentation
- Industrial controls
- Weigh scales
- Automotive controls
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.
The AD8231-EVALZ has two AD8231s mounted on it. Z1 is the AD8231 on the left side of the board. It is configured to allow access of the in-amp and op amp separately. Z2 is the AD8231 on the right side of the board. It is set up as a differential output configuration. See AD8231-EVALZ data sheet for complete instruction.
In-Amp Diamond Plot Tool
The Diamond Plot Tool is a web application that generates a configuration-specific Output Voltage Range vs. Input Common-Mode Voltage graph, also known as the Diamond Plot, for Analog Devices Instrumentation Amplifiers. Based on user inputs such as supply voltage, gain, and input signal range, the tool detects saturation and recommends in-amps for which the input signal is in-range and the configuration is valid. Avoid saturation, find the best in-amp for your design, and save time.
A wide variety of electronic applications, especially those involving very small input signals, require signal paths...
High-performance Adder Uses Instrumentation Amplifiers
Make an adder circuit using instrumentation amplifiers to increase input impedance.
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.
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.