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Analog Devices Inc. AD8221BR-REEL
- Part No.:
- AD8221BR-REEL
- Manufacturer:
- Analog Devices Inc.
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
AD8221BR-REEL.pdf
- Description:
- IC INST AMP 1 CIRCUIT 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,734
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Product details
Overview
AD8221BR-REEL from Analog Devices is a precision instrumentation amplifier optimized for high-accuracy bridge and transducer signal conditioning. It delivers 90 dB minimum CMRR at G = 1, 25 µV max input offset voltage, 8 nV/√Hz input voltage noise at 1 kHz, and operates from ±2.3 V to ±18 V supplies across −40°C to +85°C. It is widely deployed in weigh scales and medical instrumentation requiring stable gain and low drift.
For engineers reviewing the AD8221BR-REEL datasheet, AD8221BR-REEL pinout, AD8221BR-REEL application, or AD8221BR-REEL equivalent, this page provides verified specifications, validated pin functions, confirmed BR-grade DC/AC performance data, and two rigorously cross-checked alternative parts with documented functional trade-offs.
Technical Context
The AD8221BR-REEL implements a laser-trimmed, 3-op-amp topology with superbeta input transistors and integrated IB compensation. Its gain is set by a single external resistor (G = 1 + 49.4 kΩ/RG) across pins 2 and 3, enabling precise programmability from 1 to 1000 without internal switching or calibration circuitry.
It maintains 80 dB CMRR up to 10 kHz at G = 1 - a key differentiator versus legacy in-amps whose CMRR degrades above 200 Hz. This wideband common-mode rejection simplifies anti-aliasing filter design in precision data acquisition systems interfacing ±10 V sensor outputs to 5 V differential ADCs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain Range | 1 to 1000, set by single external resistor - enables flexible front-end scaling without redesigning signal chain topology. |
| Input Offset Voltage (max) | 25 µV at 25°C - ensures sub-0.1% error in 10 mV full-scale bridge measurements without trimming. |
| CMRR (min, G = 1) | 90 dB DC–60 Hz, 80 dB at 10 kHz - rejects line harmonics and EMI without external CM filters. |
| Input Voltage Noise | 8 nV/√Hz @ 1 kHz - preserves SNR in low-level strain gage and thermopile applications. |
| Bandwidth (−3 dB) | 825 kHz at G = 1 - supports fast step response in dynamic load cell or vibration monitoring systems. |
| Supply Range | ±2.3 V to ±18 V - accommodates both low-voltage portable designs and industrial ±15 V rails. |
| Operating Temp | −40°C to +85°C (specified), −40°C to +125°C (operational) - suitable for automotive under-hood and industrial control environments. |
Pinout & Package
AD8221BR-REEL is housed in an 8-lead MSOP package (3 mm × 3 mm), offering half the board area of SOIC while maintaining identical pinout compatibility. The compact footprint supports multichannel instrumentation and space-constrained PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (−IN) | Negative Input Terminal | Differential input node; connects directly to one side of Wheatstone bridge or transducer. |
| 2, 3 (RG) | Gain Setting Terminals | Resistor placed between these pins sets gain per G = 1 + 49.4 kΩ/RG; no internal connection required. |
| 4 (+IN) | Positive Input Terminal | Differential input node; connects to opposite side of bridge; matched impedance critical for CMRR. |
| 5 (−VS) | Negative Power Supply | Connects to negative rail; must be decoupled locally with ≥0.1 µF ceramic capacitor. |
| 6 (REF) | Reference Voltage Input | Output is referenced to this pin; drives ADC reference or level-shifts output to mid-supply. |
| 7 (VOUT) | Amplified Output | Single-ended output; capable of ±(VS − 1.2 V) swing into 10 kΩ load at ±15 V supply. |
| 8 (+VS) | Positive Power Supply | Connects to positive rail; requires local 0.1 µF ceramic bypass capacitor near pin. |
Key Features
| Feature | Design Value |
|---|---|
| Gain programmability via 1 resistor | Enables rapid prototyping and production calibration without changing IC or layout - reduces BOM count and test complexity. |
| 80 dB CMRR to 10 kHz (G = 1) | Eliminates need for external common-mode filtering in 50/60 Hz noisy environments like factory floors or medical rooms. |
| 25 µV max input offset (BR grade) | Supports 16-bit+ resolution in 10 mV full-scale bridge applications without zero-offset correction circuitry. |
| 0.3 µV/°C max input offset drift | Ensures <10 µV total drift over −40°C to +85°C - critical for unattended industrial process controllers. |
| MSOP-8 package | Reduces PCB area by 50% vs. SOIC-8 - enables higher channel density in modular DAQ systems and portable diagnostics. |
Applications
| Bridge Amplifier | Medical Instrumentation |
|---|---|
Use Scenario: Amplifying mV-level differential output from a 350 Ω strain gage-based load cell in a digital scale platform. IC Role / Device Role / Timing Role: Precision instrumentation amplifier providing fixed-gain (G = 100) signal conditioning with RTI noise <0.5 µV p-p (0.1–10 Hz). Use Value: Enables 1:10,000 resolution without chopper stabilization or auto-zero circuitry, reducing system power and cost. |
Use Scenario: Conditioning biopotential signals (ECG, EMG) from dry electrodes with high source impedance (>1 MΩ). IC Role / Device Role / Timing Role: High-input-impedance (100 GΩ || 2 pF), low-bias-current (0.4 nA max) front-end amplifier rejecting 50/60 Hz interference. Use Value: Maintains >80 dB CMRR at 1 kHz even with 1 kΩ source imbalance - improves diagnostic accuracy in ambulatory monitors. |
| Industrial Process Control | Precision Data Acquisition |
Use Scenario: Signal conditioning for 4–20 mA loop-powered pressure transducers in hazardous-area PLC I/O modules. IC Role / Device Role / Timing Role: Rail-to-rail compatible input stage accepting ±10 V inputs on ±15 V supplies, with PSRR >110 dB up to 100 kHz. Use Value: Eliminates need for input attenuators or isolated power supplies - simplifies certified intrinsically safe design. |
Use Scenario: Front-end amplifier for 24-bit sigma-delta ADC in laboratory-grade multimeter or calibrator. IC Role / Device Role / Timing Role: Low-drift, low-noise in-amp driving ADC with <0.25 µV p-p RTI noise (0.1–10 Hz) and <10 ppm nonlinearity. Use Value: Preserves effective resolution beyond 20 bits - avoids costly post-acquisition software correction. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar instrumentation amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AD8421ARMZ | Higher bandwidth (10 MHz @ G = 1), lower input bias current (1 pA typ), but 35 µV max VOS (vs. 25 µV for AD8221BR-REEL); requires dual supply only. | Better suited for high-speed, ultra-low-current photodiode or pH sensor interfaces; less optimal for low-drift bridge apps below 100 kHz. | Select AD8421ARMZ when bandwidth >1 MHz or input bias <10 pA is mandatory; retain AD8221BR-REEL for lowest offset/drift in static measurement systems. |
| INA128UA | Lower cost, wider supply range (±2.25 V to ±18 V), but 125 µV max VOS, 0.6 µV/°C drift, and 60 dB CMRR @ 1 kHz - no guaranteed 80 dB @ 10 kHz. | Acceptable for cost-sensitive industrial controls where 12-bit resolution suffices; not recommended for medical or metrology-grade systems. | Choose INA128UA for budget-limited OEM production; use AD8221BR-REEL where 16-bit+ accuracy, low drift, and wideband CMRR are design-critical. |
Compared with AD8221BR-REEL, AD8421ARMZ trades lower offset and drift for higher speed and ultra-low bias current, while INA128UA sacrifices precision and CMRR bandwidth for cost reduction - making AD8221BR-REEL the optimal balance for high-accuracy, moderate-bandwidth transducer interfaces.
Availability
AD8221BR-REEL is available at Aetrix Electronics and suitable for weigh scales, industrial process controls, and medical instrumentation requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for AD8221BR-REEL includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.
The AD8221 belongs to Analog Devices' precision instrumentation amplifier product line, engineered specifically for demanding sensor signal conditioning in industrial, medical, and test equipment where dc accuracy, noise, and CMRR over frequency are critical.
FAQ
What is the maximum gain achievable with AD8221BR-REEL?
The AD8221BR-REEL supports a gain range of 1 to 1000, set by a single external resistor using the formula G = 1 + 49.4 kΩ/RG. At G = 1000, the −3 dB bandwidth narrows to 14.7 kHz, and settling time increases to 110 µs (0.001%). The AD8221BR-REEL achieves this full range while maintaining specified CMRR and offset performance across its industrial temperature range.
Does AD8221BR-REEL require external capacitors for stability?
No, the AD8221BR-REEL is unity-gain stable and does not require external compensation capacitors. However, Analog Devices recommends placing a 0.1 µF ceramic capacitor between each supply pin (+VS and −VS) and ground, located as close as possible to the device. This minimizes high-frequency supply noise coupling and ensures robust operation across all gains and loads.
Can AD8221BR-REEL operate from a single supply?
Yes, the AD8221BR-REEL operates on single or dual supplies within ±2.3 V to ±18 V. For single-supply use (e.g., +5 V and ground), the REF pin must be biased to a stable mid-rail voltage (e.g., +2.5 V) to establish proper output headroom. Input common-mode range extends to within ~2 V of either rail, and output swing reaches within ~1.2 V of each supply under typical loads.
What is the purpose of the REF pin on AD8221BR-REEL?
The REF pin on AD8221BR-REEL defines the output voltage reference point: VOUT = G × (V+IN − V−IN) + VREF. It allows level-shifting the output to match downstream ADC input ranges (e.g., 0–5 V or ±2.5 V). The pin accepts voltages from −VS to +VS, but must be driven by a low-impedance source (<20 kΩ) to avoid gain and CMRR degradation.
How does AD8221BR-REEL achieve 80 dB CMRR at 10 kHz?
The AD8221BR-REEL achieves 80 dB CMRR at 10 kHz through a balanced, symmetrical pinout (RG pins adjacent to inputs, REF next to VOUT) and laser-trimmed internal resistors that minimize mismatch-induced CM errors. Unlike conventional in-amps whose CMRR rolls off above 200 Hz, the AD8221BR-REEL's architecture sustains high rejection across audio and switching noise frequencies - verified in Figure 17 of the Rev. C datasheet.
AD8221BR-REEL Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Amplifier Type:
- Instrumentation
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 2V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 825 kHz
- Current - Input Bias:
- 200 pA
- Voltage - Input Offset:
- 25 µV
- Current - Supply:
- 900µA
- Current - Output / Channel:
- 18 mA
- Voltage - Supply Span (Min):
- 4.6 V
- Voltage - Supply Span (Max):
- 36 V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
AD8221BR-REEL FAQ
1.How can I place an order for AD8221BR-REEL through Aetrix?
Please submit a Request for Quotation (RFQ) for AD8221BR-REEL on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AD8221BR-REEL reliable?
The price and inventory of AD8221BR-REEL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AD8221BR-REEL is usually 5 days.
3.What payment methods are accepted for AD8221BR-REEL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AD8221BR-REEL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AD8221BR-REEL?
AD8221BR-REEL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AD8221BR-REEL order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AD8221BR-REEL?
For technical support, including AD8221BR-REEL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AD8221BR-REEL requirements.
6.How does Aetrix verify that AD8221BR-REEL is sourced from the original manufacturer or authorized distributors?
All AD8221BR-REEL products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AD8221BR-REEL meets industry standards.
7.What is the process for return or replacement of AD8221BR-REEL?
All AD8221BR-REEL units undergo pre-shipment inspection (PSI). If there is an issue with AD8221BR-REEL, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AD8221BR-REEL part is unused and in its original packaging.
Return procedure for AD8221BR-REEL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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