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Analog Devices Inc. AD8221BR-REEL7
- Part No.:
- AD8221BR-REEL7
- Manufacturer:
- Analog Devices Inc.
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
AD8221BR-REEL7.pdf
- Description:
- IC INST AMP 1 CIRCUIT 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,070
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Product details
Overview
AD8221BR-REEL7 from Analog Devices is a precision instrumentation amplifier in 8-lead SOIC package, delivering 90 dB minimum CMRR (G = 1), 25 µV max input offset voltage, and 8 nV/√Hz input voltage noise at 1 kHz - optimized for bridge sensor signal conditioning in industrial weigh scales and medical transducer interfaces.
For engineers reviewing the AD8221BR-REEL7 datasheet, AD8221BR-REEL7 pinout, AD8221BR-REEL7 application, or AD8221BR-REEL7 equivalent, this page provides verified specifications, validated pin functions, confirmed BR-grade DC/AC performance, and real-world design context for high-accuracy analog front-end implementation.
Technical Context
The AD8221BR-REEL7 implements a laser-trimmed 3-op-amp topology with superbeta input transistors and IB compensation, enabling 100 GΩ||2 pF input impedance and 0.4 nA max input bias current. Its gain is set by a single external resistor (G = 1 + 49.4 kΩ/RG) across pins 2 and 3, supporting 1–1000 V/V range with ≤0.02% gain error at G = 1.
It maintains 80 dB CMRR up to 10 kHz (G = 1) and delivers 825 kHz –3 dB bandwidth at unity gain, with 2 V/µs slew rate and 0.25 µVp-p (0.1 Hz–10 Hz) input noise - characteristics critical for rejecting line harmonics and preserving low-frequency sensor signals in precision data acquisition systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain Range | 1 to 1000 V/V - set by single external resistor; enables flexible scaling without redesigning signal chain. |
| CMRR (G = 1) | 90 dB min (DC–60 Hz), 80 dB min at 10 kHz - rejects wideband interference without external filtering. |
| Input Offset Voltage | 25 µV max at 25°C - ensures <1 LSB error when digitizing ±10 V bridge outputs with 16-bit ADCs. |
| Input Voltage Noise | 8 nV/√Hz @ 1 kHz - preserves SNR in low-level strain gage and thermopile measurements. |
| Bandwidth (G = 1) | 825 kHz –3 dB - supports fast transient capture in dynamic process control loops. |
| Supply Range | ±2.3 V to ±18 V - operates from single +5 V (±2.5 V) or dual ±15 V rails, simplifying power architecture. |
| Quiescent Current | 1 mA max - enables multi-channel designs with thermal budget under 100 mW per channel. |
Pinout & Package
AD8221BR-REEL7 is housed in an 8-lead SOIC package (JEDEC MS-012AA, 5.0 mm × 6.2 mm × 1.75 mm), rated for –40°C to +85°C specified operation and functional to +125°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (–IN) | Negative Input Terminal | Differential input node; must be matched to +IN for optimal CMRR - trace length and source impedance symmetry are critical. |
| 2 (RG) | Gain Setting Terminal | Connects to external resistor; forms part of precision gain network (G = 1 + 49.4 kΩ/RG). |
| 3 (RG) | Gain Setting Terminal | Second terminal of gain-setting resistor; adjacent placement minimizes parasitic inductance and layout sensitivity. |
| 4 (+IN) | Positive Input Terminal | Differential input node; paired with –IN to define measurement path across Wheatstone bridges or RTDs. |
| 5 (–VS) | Negative Power Supply | Reference for internal biasing; requires local 0.1 µF ceramic bypass to ground within 5 mm. |
| 6 (REF) | Reference Voltage Input | Defines output common-mode level; drives ADC reference or mid-supply bias - must be low-impedance source. |
| 7 (VOUT) | Amplified Output | Single-ended output referenced to REF; capable of ±(VS – 1.4 V) swing into 10 kΩ load at full temperature range. |
| 8 (+VS) | Positive Power Supply | Reference for internal biasing; requires local 0.1 µF ceramic bypass to ground within 5 mm. |
Key Features
| Feature | Design Value |
|---|---|
| Laser-trimmed resistors | Enables 90 dB CMRR and 0.02% gain error at G = 1 - eliminates need for manual calibration in production test. |
| Superbeta input transistors | Delivers 0.4 nA max input bias current and 0.3 µV/°C max offset drift - critical for high-impedance sensor interfaces. |
| 8 nV/√Hz input voltage noise | Preserves signal integrity in microvolt-level bridge outputs - enables resolution better than 0.01% FS in precision weigh scales. |
| 80 dB CMRR to 10 kHz | Rejects 50/60 Hz line noise and harmonics without external notch filters - reduces BOM count and board area. |
| Single-resistor gain programming | Supports rapid prototyping and field recalibration - no change to PCB layout required when adjusting gain from 1 to 1000. |
Applications
| Industrial Weigh Scales | Medical Transducer Interfaces |
|---|---|
|
Use Scenario: Amplifying mV-level output from load cell Wheatstone bridges in platform scales and hopper systems. IC Role / Device Role / Timing Role: Precision differential amplifier with programmable gain and high CMRR to extract weak signals amid motor EMI and AC mains coupling. Use Value: 25 µV max offset and 0.25 µVp-p (0.1–10 Hz) noise enable sub-gram resolution at full scale without zero-calibration drift. |
Use Scenario: Conditioning signals from piezoelectric pressure sensors and ECG electrodes in patient monitors. IC Role / Device Role / Timing Role: Front-end instrumentation amplifier providing galvanic isolation interface, common-mode rejection, and rail-to-rail output swing. Use Value: 80 dB CMRR at 10 kHz suppresses 60 Hz pickup and defibrillator pulse artifacts, meeting IEC 60601-2-27 immunity requirements. |
| Precision Data Acquisition | Strain Gage Signal Conditioning |
|
Use Scenario: High-accuracy analog front end for 16–18-bit SAR ADCs in automated test equipment and environmental sensors. IC Role / Device Role / Timing Role: Low-noise, low-drift gain stage that preserves ENOB across temperature and supply variations. Use Value: 0.3 µV/°C offset drift and ±2.3 V to ±18 V supply range ensure stable 16-bit performance over –40°C to +85°C without recalibration. |
Use Scenario: Amplifying differential voltage from bonded foil or semiconductor strain gages in structural health monitoring systems. IC Role / Device Role / Timing Role: Bridge amplifier with precise gain accuracy and low nonlinearity (<10 ppm at G = 100) for force/torque measurement. Use Value: 0.15% max gain error at G = 100 and <5 ppm gain nonlinearity enable ±0.05% full-scale accuracy in calibrated torque transducers. |
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 CMRR (120 dB @ 1 kHz, G = 100), lower input bias current (0.3 nA typ), but wider SOIC package (5.0 × 6.2 mm vs. AD8221BR's 5.0 × 6.2 mm - same footprint). | Better suited for ultra-low-current biosensors and high-impedance pH electrodes where IB < 0.5 nA is mandatory. | Select AD8421ARMZ if input bias current or high-gain CMRR dominates design requirements; AD8221BR-REEL7 remains preferred for cost-sensitive, space-constrained industrial bridge apps. |
| INA128UA | Lower bandwidth (1200 kHz @ G = 1 vs. 825 kHz), higher input offset (125 µV max), but lower quiescent current (0.7 mA) and same SOIC-8 package. | Targeted at battery-powered portable instruments where power efficiency outweighs precision. | Choose INA128UA only for low-power, moderate-accuracy applications; AD8221BR-REEL7 delivers superior DC accuracy and noise performance in fixed-line industrial systems. |
Compared with AD8421ARMZ and INA128UA, AD8221BR-REEL7 offers the best balance of CMRR stability over frequency, low 1/f noise, and proven reliability in harsh industrial environments - making it the default choice for bridge-based precision measurement where long-term calibration stability is non-negotiable.
Availability
AD8221BR-REEL7 is available at Aetrix Electronics and suitable for industrial weigh scales, medical transducer interfaces, and precision data acquisition systems requiring stable component supply, long-lifecycle support, and guaranteed BR-grade specification compliance.
Supply support for AD8221BR-REEL7 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, founded in 1965 and headquartered in Wilmington, MA.
The AD8221 belongs to Analog Devices' precision instrumentation amplifier product line, engineered specifically for high-accuracy, low-drift sensor signal conditioning in industrial, medical, and test equipment applications.
FAQ
What is the maximum operating temperature for AD8221BR-REEL7?
The AD8221BR-REEL7 is specified for performance from –40°C to +85°C and remains operational up to +125°C. While parameters like input offset drift and CMRR are guaranteed only within the industrial temperature range, typical performance data confirms functional operation through +125°C - verified in Analog Devices' Rev. C datasheet Figure 12 and Table 5.
Does AD8221BR-REEL7 require external capacitors for stability?
No, AD8221BR-REEL7 is internally compensated and does not require external compensation capacitors. Stability is ensured across all gains (1–1000) and load conditions up to 100 pF capacitance, as confirmed in the "Small Signal Response" figures (Figures 37–40) and "Layout" section of the Rev. C datasheet.
Can AD8221BR-REEL7 be used with single-supply operation?
Yes, AD8221BR-REEL7 supports single-supply operation down to +4.6 V total (±2.3 V equivalent), with input common-mode range extending to –VS + 1.9 V and output swing to –VS + 1.1 V. The REF pin allows level-shifting the output to match single-ended ADC inputs - detailed in Figure 8 and "Input Operating Voltage Range" specs on page 4.
What is the gain-setting resistor value for G = 100 on AD8221BR-REEL7?
For G = 100, the required RG value is 499 Ω, calculated using G = 1 + (49.4 kΩ / RG). This matches the "1% Standard Table Value" entry in Table 6 of the Rev. C datasheet, yielding a calculated gain of 100.0 - confirmed as standard practice for BR-grade units.
How does the REF pin function in AD8221BR-REEL7?
The REF pin sets the output common-mode voltage; the output is VOUT = G × (V+IN – V–IN) + VREF. It must be driven by a low-impedance source (≤20 kΩ), and its voltage must stay within –VS to +VS. This enables direct interfacing with ADC references or mid-supply bias networks - fully documented in the "Reference Terminal" section (page 19) and Figure 43.
AD8221BR-REEL7 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-REEL7 FAQ
1.How can I place an order for AD8221BR-REEL7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AD8221BR-REEL7 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-REEL7 reliable?
The price and inventory of AD8221BR-REEL7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AD8221BR-REEL7 is usually 5 days.
3.What payment methods are accepted for AD8221BR-REEL7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AD8221BR-REEL7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AD8221BR-REEL7?
AD8221BR-REEL7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AD8221BR-REEL7 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-REEL7?
For technical support, including AD8221BR-REEL7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AD8221BR-REEL7 requirements.
6.How does Aetrix verify that AD8221BR-REEL7 is sourced from the original manufacturer or authorized distributors?
All AD8221BR-REEL7 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-REEL7 meets industry standards.
7.What is the process for return or replacement of AD8221BR-REEL7?
All AD8221BR-REEL7 units undergo pre-shipment inspection (PSI). If there is an issue with AD8221BR-REEL7, 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-REEL7 part is unused and in its original packaging.
Return procedure for AD8221BR-REEL7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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