AD8221ARZ - Precision Instrumentation Amplifier | Analog Devices
MPN: AD8221ARZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.86 | $4.86 |
| 10 | $4.36 | $43.60 |
| 100 | $3.88 | $388.00 |
| 500 | $3.49 | $1,745.00 |
| 1,000 | $3.29 | $3,290.00 |
Drop-in alternatives for AD8221ARZ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD8221BRZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD8223ARZ
✅ Drop-In✓ In Stock
$2.46 / Unit
View Datasheet →AD8227ARZ
✅ Drop-In✓ In Stock
$3.1 / Unit
View Datasheet →AD8422ARZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD620ARZ
✅ Drop-In✓ In Stock
$7.2 / Unit
View Datasheet →AD8221ARZ Maximum Ratings & Electrical Characteristics
| Amplifier Type | Instrumentation |
| Number of Circuits | 1 |
| Gain Bandwidth Product | 825 kHz |
| Slew Rate | 2 V/µs |
| Input Offset Voltage | 60 µV |
| Input Bias Current | 500 pA |
| CMRR | 90 dB min at 60 Hz, 80 dB min at 10 kHz |
| Supply Voltage - Single | 4.5 V to 36 V |
| Supply Voltage - Dual | ±2.25 V to ±18 V |
| Quiescent Current | 1.2 mA |
| Gain Range | 1 to 1000 |
| Package | 8-SOIC |
| Operating Temperature Range | -40°C to +85°C |
| RoHS | Compliant |
| Mounting Type | Surface Mount |
AD8221ARZ Pin Configuration
| Pin 1 | RG — Gain setting resistor connection |
| Pin 2 | -IN — Inverting input |
| Pin 3 | +IN — Non-inverting input |
| Pin 4 | V- — Negative supply |
| Pin 5 | REF — Reference voltage input |
| Pin 6 | OUT — Output |
| Pin 7 | V+ — Positive supply |
| Pin 8 | RG — Gain setting resistor connection |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
AD8221ARZ is suitable for 6 applications: Medical Instrumentation, Industrial Process Control, Bridge Amplifiers, Data Acquisition Systems, Precision Sensor Interfaces, Automotive Sensor Conditioning.
Medical Instrumentation
The AD8221ARZ is ideal for ECG and EEG systems due to its high CMRR of 90 dB at 60 Hz, which rejects power-line interference. Its low input offset voltage of 60 µV and low bias current of 500 pA ensure accurate biopotential measurements. The wide supply range allows operation from battery or mains power, and the small SOIC package enables compact wearable devices.
Recommended
Industrial Process Control
In industrial settings, the AD8221ARZ provides precise amplification of sensor signals from bridges, thermocouples, and strain gauges. Its high CMRR over frequency rejects common-mode noise from motors and power lines. The gain range of 1 to 1000 allows flexible scaling of various sensor outputs. The device's robust supply range of ±18 V and industrial temperature range ensure reliable operation in harsh factory environments.
Recommended
Bridge Amplifiers
The AD8221ARZ excels in bridge amplifier applications, such as load cells and pressure sensors, where its low offset voltage and high CMRR are critical. The device's three-op-amp architecture provides excellent linearity and stability. With a gain set by a single resistor, it simplifies calibration. The low quiescent current of 1.2 mA makes it suitable for battery-powered portable scales.
Recommended
Data Acquisition Systems
The AD8221ARZ is a key component in data acquisition systems, providing clean amplification of sensor signals before ADC conversion. Its 825 kHz bandwidth supports high-speed sampling, while the low noise and high CMRR ensure signal integrity. The device's small SOIC package and wide supply range make it versatile for both portable and benchtop systems. It pairs well with high-resolution ADCs for accurate measurements.
Recommended
Precision Sensor Interfaces
The AD8221ARZ is designed for precision sensor interfaces, such as thermocouple and RTD conditioning. Its low input bias current of 500 pA minimizes loading on high-impedance sensors, and the high CMRR rejects common-mode noise. The gain range of 1 to 1000 allows direct connection to various sensor outputs. The device's low offset voltage ensures accurate temperature readings.
Recommended
Automotive Sensor Conditioning
In automotive applications, the AD8221ARZ conditions signals from pressure, temperature, and position sensors. Its high CMRR over frequency rejects noise from the vehicle's electrical system. The wide supply range of 4.5 V to 36 V accommodates automotive battery voltages. The device's industrial temperature range and small SOIC package make it suitable for engine control units and body electronics.
Recommended
Recommended Products Summary
Engineering reference data for AD8221ARZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD8221BRZ | AD8223ARZ | AD8227ARZ | AD8422ARZ | AD620ARZ |
|---|---|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| CMRR at 60 Hz | 90 dB min | 90 dB min | 80 dB min | 80 dB min | 90 dB min | 86 dB min |
| Input Offset Voltage | 60 µV | 25 µV | 60 µV | 60 µV | 60 µV | 50 µV |
| Input Bias Current | 500 pA | 500 pA | 500 pA | 500 pA | 500 pA | 1 nA |
| Bandwidth | 825 kHz | 825 kHz | 200 kHz | 250 kHz | 2.2 MHz | 120 kHz |
| Supply Voltage Range | 4.5 V to 36 V | 4.5 V to 36 V | 4.5 V to 36 V | 2.7 V to 36 V | 4.5 V to 36 V | 4.5 V to 36 V |
| Quiescent Current | 1.2 mA | 1.2 mA | 1.5 mA | 1.2 mA | 1.2 mA | 1.3 mA |
Key Differentiators
- Highest CMRR over frequency in its class (vs AD620ARZ)
- Lower input bias current (vs AD620ARZ)
- Higher bandwidth (vs AD8223ARZ)
Design Notes
Place a 0.1 µF ceramic capacitor close to each supply pin (V+ and V-) and a 10 µF tantalum capacitor for low-frequency decoupling. This ensures stable operation and maintains high CMRR by minimizing supply noise. Use a ground plane to reduce noise pickup.
Keep the gain-setting resistor (RG) close to the RG pins (pins 1 and 8) to minimize parasitic capacitance and inductance, which can affect gain accuracy and bandwidth. Use short, direct traces and avoid routing high-speed signals near the input pins.
Do not exceed the absolute maximum supply voltage of 36 V. Ensure the reference pin (pin 5) is properly driven to avoid output saturation. In single-supply applications, connect the reference pin to a mid-supply voltage to allow bipolar output swing.
Compliance Information
RoHS compliance confirmed by 'Z' suffix in part number. Other compliance data not specified in provided sources.
