AD8221ARZ - Precision Instrumentation Amplifier | Analog Devices
MPN： AD8221ARZ ✓ 啟用中AD8221ARZ 概覽
An instrumentation amplifier is a type of differential amplifier that amplifies the difference between two input signals while rejecting common-mode voltages. It is characterized by high input impedance, low offset voltage, and high CMRR, making it ideal for precise sensor signal conditioning. Instrumentation amplifiers are a subset of operational amplifiers, which are fundamental building blocks in analog signal processing, and they are widely used in medical, industrial, and automotive applications.
Key features of the AD8221ARZ include a low input offset voltage of 60 µV, a low input bias current of 500 pA, and a bandwidth of 825 kHz. The device also offers a slew rate of 2 V/µs, ensuring fast response in dynamic measurement systems. The gain is set by a single external resistor, allowing flexible configuration from 1 to 1000. The high CMRR of 90 dB at 60 Hz (minimum) and 80 dB at 10 kHz (minimum) ensures accurate rejection of power-line interference and high-frequency noise.
The AD8221ARZ is designed with a three-op-amp architecture, providing excellent DC and AC performance. The input stage uses super-beta transistors to achieve low bias current, while the output stage drives loads up to 10 kΩ. The device operates from a single supply of 4.5 V to 36 V or dual supplies of ±2.25 V to ±18 V, with a quiescent current of 1.2 mA. The wide supply range and low power consumption make it suitable for battery-powered and industrial applications.
Typical applications include medical instrumentation (ECG, EEG), industrial process control, bridge amplifiers, and data acquisition systems. The AD8221ARZ is also used in precision sensor interfaces, where its low offset and high CMRR are critical for accurate measurements. Its small SOIC package and surface-mount design enable compact PCB layouts.
When designing with the AD8221ARZ, ensure proper grounding and decoupling to maintain high CMRR. Use a 0.1 µF capacitor close to the supply pins and a 10 µF tantalum capacitor for low-frequency decoupling. The reference pin (pin 5) can be used to level-shift the output, which is useful in single-supply applications.
直接替換替代品，適用於 AD8221ARZ — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： AD8221ARZ （相同外形與佔位） — 差異在於 Gain Range, Package, Input Offset Voltage, Input Bias Current, Slew Rate.
AD8221BRZ
✅ 直接替換📋 參考替代品（不在目錄中）
AD8223ARZ
✅ 直接替換聯絡詢價
查看資料表 →AD8227ARZ
✅ 直接替換聯絡詢價
查看資料表 →AD8422ARZ
✅ 直接替換📋 參考替代品（不在目錄中）
AD8221ARZ 最大額定值與電氣特性
| 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 |
| 靜態電流 | 1.2 mA |
| Gain Range | 1 to 1000 |
| 封裝 | 8-SOIC |
| 工作溫度範圍 | -40°C to +85°C |
| RoHS | Compliant |
| 安裝類型 | Surface Mount |
AD8221ARZ 腳位配置
| 腳位 1 | RG — Gain setting resistor connection |
| 腳位 2 | -IN — Inverting input |
| 腳位 3 | +IN — Non-inverting input |
| 腳位 4 | V- — Negative supply |
| 腳位 5 | REF — Reference voltage input |
| 腳位 6 | OUT — Output |
| 腳位 7 | V+ — Positive supply |
| 腳位 8 | RG — Gain setting resistor connection |
典型應用
AD8221ARZ 適用於 6 應用s: 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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
推薦產品摘要
工程參考資料，適用於 AD8221ARZ — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | 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 |
主要差異化特點
- Highest CMRR over frequency in its class (對比AD620ARZ)
- Lower input bias current (對比AD620ARZ)
- Higher bandwidth (對比AD8223ARZ)
設計說明
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.
合規資訊
RoHS compliance confirmed by 'Z' suffix in part number. Other compliance data not specified in provided sources.
