The AD8221 is a gain programmable, high performance instrumentation amplifier that delivers the industry’s highest CMRR over frequency in its class. The CMRR of instrumentation amplifiers on the market today falls off at 200 Hz. In contrast, the AD8221 maintains a minimum CMRR of 80 dB to 10 kHz for all grades at G = 1. High CMRR over frequency allows the AD8221 to reject wideband interference and line harmonics, greatly simplifying filter requirements. Possible applications include precision data acquisition, biomedical analysis, and aerospace instrumentation.
Low voltage offset, low offset drift, low gain drift, high gain accuracy, and high CMRR make this part an excellent choice in applications that demand the best dc performance possible, such as bridge signal conditioning.
Programmable gain affords the user design flexibility. A single resistor sets the gain from 1 to 1000. The AD8221 operates on both single and dual supplies and is well suited for applications where ±10 V input voltages are encountered.
The AD8221 is available in a low cost 8-lead SOIC and 8-lead MSOP, both of which offer the industry’s best performance. The MSOP requires half the board space of the SOIC, making it ideal for multichannel or space-constrained applications.
Performance is specified over the entire industrial temperature range of −40°C to +85°C for all grades. Furthermore, the AD8221 is operational from −40°C to +125°C*.
|Title||Content Type||File Type|
|AD8221: Precision Instrumentation Amplifier Data Sheet (Rev C, 03/2011) (pdf, 701 kB)||Data Sheets|
|AN-282: Fundamentals of Sampled Data Systems (pdf, 2131 kB)||Application Notes|
|AN-671: Reducing RFI Rectification Errors in In-Amp Circuits (pdf, 208 kB)||Application Notes|
|AN-683: Strain Gage Measurement Using an AC Excitation (pdf, 122 kB)||Application Notes|
|CN-0114: Low Cost, High Voltage, Programmable Gain Instrumentation Amplifier Using the AD5292 Digital Potentiometer and the AD8221 In-Amp (pdf, 155 kB)||Circuit Note|
|A Designer's Guide to Instrumentation Amplifiers (3rd Edition)||Design Handbooks||HTML|
|UG-261: Evaluation Boards for the AD62x, AD822x and AD842x Series (pdf, 604 kB)||User Guides|
|MS-2178: Discussion Between CareFusion and Analog Devices: Optimizing Performance and Lowering Power in an EEG Amplifer (pdf, 147 kB)||Technical Articles|
|MS-2160: Mitigation Strategies for ECG Design Challenges (pdf, 205 kB)||Technical Articles|
Eye Movement Controls Gaming Console
(EE Times, 11/4/2010)
(doc, 75 kB)
A wide variety of electronic applications, especially those involving very small input signals, require signal paths with very low offset voltage and offset voltage drift over time and temperature.
High-performance Adder Uses Instrumentation Amplifiers
Make an adder circuit using instrumentation amplifiers to increase input impedance.
Input Filter Prevents Instrumentation-amp RF-Rectification Errors
by Charles Kitchin, Lew Counts, and Moshe Gerstenhaber, Analog Devices, Inc. (EDN, 11/13/2003)
|The AD8221 - Setting a New Industry Standard for Instrumentation Amplifiers (pdf, 582 kB)||Technical Articles|
|Applying Instrumentation Amplifiers Effectively: The Importance of an Input Ground Return (pdf, 508 kB)||Technical Documentation|
analogZONE Reviews the AD8221
(February 10, 2003)
Dual In-Amp And Signal Isolators Sweat The Small Stuff
|DigiPot Circuits from the Lab||Overview||HTML|
|Optimum process control means efficiency, reliability, and Analog ICs.||Overview||HTML|
|Leading Inside Advertorials: Applying Instrumentation Amplifiers EffectivelyThe Importance of an Input Ground Return (pdf, 121 kB)||Overview|
|RAQs index||Rarely Asked Questions||HTML|
|Glossary of EE Terms||Glossary||HTML|
|Title||Content Type||File Type|
|AD8221 SPICE Macro-Model||SPICE Models||HTML|
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.