INA122U - 36V Micropower Instrumentation Amplifier | TI
料号： INA122U ✓ 量产中INA122U 概述
What is an instrumentation amplifier? An instrumentation amplifier is a differential amplifier optimized for measuring a small voltage difference between two inputs while rejecting common-mode interference. In the signal-chain hierarchy, an instrumentation amplifier sits between a sensor and a higher-level processing circuit; it provides gain, input impedance, and common-mode rejection in one dedicated analog block. Unlike a general-purpose operational amplifier, an instrumentation amplifier is intended for differential sensing and often preserves signal integrity when large common-mode voltages are present.
Key features of the INA122U include a low quiescent current of 60 µA, wide supply operation from 2.2 V to 36 V, a common-mode range extending to (V−) − 0.1 V, rail-to-rail output swing, low offset voltage of 250 µV maximum, low offset drift of 3 µV/°C maximum, and low noise. The 8-SOIC package supports conventional surface-mount assembly and is identified by DigiKey as a one-circuit instrumentation amplifier.
The two-op-amp architecture provides a straightforward gain-setting network while keeping the device suitable for portable and low-power systems. The INA122U is designed for accurate, low-noise differential signal acquisition rather than high-speed waveform processing. Its supply flexibility allows operation from a compact single supply or from dual supplies up to ±18 V, depending on the application requirements. The low 60 µA quiescent current helps limit battery drain when the amplifier is part of a portable instrument.
Typical applications include low-level sensor front ends, portable medical monitoring, strain and pressure measurement, battery-powered data acquisition, current sensing, and industrial process instrumentation. The device is particularly useful when a small differential signal must be amplified before conversion by an ADC. In these systems, the engineer should verify the selected gain against the input range, common-mode voltage, output swing, supply voltage, and settling requirements.
The main design consideration is ensuring that the input and output signals remain within the device's electrical limits while the external gain network is selected correctly. Input filtering, proper grounding, stable reference connections, and PCB trace symmetry help preserve differential accuracy. The INA122U combines low power, flexible supply operation, and precision-oriented specifications in a compact package for portable and measurement applications.
This page summarizes the verified manufacturer information, distributor listing, practical application guidance, and available comparison context for engineers evaluating INA122U. Because detailed gain-current, noise-density, bandwidth, and package-temperature data are not all present in the supplied source material, those values should be confirmed against the current Texas Instruments datasheet before final design release.
直接替换替代料： INA122U ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： INA122U （相同外形与封装尺寸） ——差异在于 Package, Product Type, Supply Voltage Range, Quiescent Current, Architecture.
INA826AID
✅ 直接替换📋 参考替代料（不在目录中）
INA826AIDR
✅ 直接替换📋 参考替代料（不在目录中）
AD8422BRZ
✅ 直接替换📋 参考替代料（不在目录中）
INA333AIDGKR
✅ 直接替换联系询价
查看数据手册 →INA122U 最大额定值与电气特性
| Product Type | Precision instrumentation amplifier |
| Architecture | Two-op-amp design |
| Supply Voltage Range | 2.2 V to 36 V |
| Single-Supply Operation | 2.2 V to 36 V |
| Dual-Supply Operation | ±18 V |
| 静态电流 | 60 µA typical |
| Common-Mode Range | (V−) − 0.1 V |
| Output Swing | Rail-to-rail output swing |
| Offset Voltage | 250 µV maximum |
| Offset Drift | 3 µV/°C maximum |
| Noise | Low noise |
| Circuit Count | 1 circuit |
| 封装 | 8-SOIC |
| Terminal Count | 8 terminals |
| 安装类型 | Surface mount |
| Application Category | Portable medical and data acquisition |
INA122U 8-soic 引脚配置指南
INA122U（8-soic 封装）的引脚配置。 该模拟元件具有输入、输出和电源引脚。请参阅制造商数据手册以了解失调调零、补偿和使能引脚配置。适用于信号调理和放大器电路。
暂无详细引脚数据： INA122U.
请参阅 数据手册 以查看完整引脚配置。
典型应用
INA122U 适用于 6 应用s: Portable Medical Sensor Front End, Battery-Powered Data Acquisition, Strain and Pressure Measurement, Current Sensing and Power Monitoring, Industrial Process Instrumentation, Portable Environmental Monitoring.
Portable Medical Sensor Front End
The INA122U fits portable medical sensor front ends because its 60 µA typical quiescent current limits supply demand while its differential-input architecture amplifies small signals before conversion. A 2.2 V to 36 V operating range allows operation from compact battery systems or higher-voltage instrumentation rails. The design should still verify input common-mode voltage, output swing, isolation requirements, and application-specific safety standards.
推荐
Battery-Powered Data Acquisition
INA122U is suitable for battery-powered data-acquisition modules that need to measure differential sensor outputs over a broad supply range. Its 60 µA typical quiescent current helps reduce continuous supply load, while the two-op-amp architecture provides gain-setting flexibility. Use suitable input filtering and an ADC front end, and confirm settling and bandwidth requirements for the selected measurement rate.
推荐
Strain and Pressure Measurement
The INA122U can amplify the small differential output generated by strain gauges, pressure sensors, and bridge transducers. Its low offset voltage of 250 µV maximum and offset drift of 3 µV/°C maximum help preserve measurement integrity as temperature and operating conditions vary. The external gain resistor network and input filtering should be matched to the bridge excitation, sensor impedance, and required output range.
推荐
Current Sensing and Power Monitoring
INA122U can serve as the analog gain stage in current-shunt monitoring when the shunt differential voltage must be amplified before measurement. The common-mode range extending to (V−) − 0.1 V supports systems where the shunt voltage sits close to the lower supply rail. Verify that the shunt common-mode voltage remains within the input limits at minimum and maximum line or load conditions.
推荐
Industrial Process Instrumentation
The INA122U fits industrial process-instrumentation front ends that require differential measurement from sensors operating above ground. Its 2.2 V to 36 V supply range and rail-to-rail output swing provide flexibility for 3.3 V, 5 V, and higher-voltage analog sections. The circuit should include protection against transients and confirm common-mode limits, gain accuracy, and output-headroom behavior in the final operating environment.
推荐
Portable Environmental Monitoring
INA122U is suitable for portable environmental-monitoring equipment where low power helps extend operating time between battery charges. Differential amplification can reduce sensitivity to common-mode noise on sensor wiring, while the 2.2 V to 36 V supply range supports multiple portable architectures. The system designer should evaluate sensor excitation, input protection, cable length, grounding, and the amplifier's settling behavior before selecting the gain network.
推荐
推荐产品汇总
工程参考数据： INA122U ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | INA826AID | INA826AIDR | AD8422BRZ | INA333AIDGKR | AD623ANZ |
|---|---|---|---|---|---|---|
| Package | 8-SOIC | SOIC-8 | SOIC-8 | SOIC-8 | VSSOP-8 | SOIC-8 |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices | Texas Instruments | Analog Devices |
| Product Function | Precision instrumentation amplifier | Instrumentation amplifier | Instrumentation amplifier | Instrumentation amplifier | Low-voltage instrumentation amplifier | Instrumentation amplifier |
关键差异点
- Very low quiescent current for an instrumentation amplifier （对比 AD623ANZ)
- Wide single-supply operating range （对比 AD8422BRZ)
- Low offset specifications for portable measurement （对比 INA826AID)
设计说明
Calculate the amplifier's supply current budget from the 60 µA typical quiescent current plus input, load, and external-network current. For battery-powered designs, include regulator efficiency and the current required by the ADC or sensor because the instrumentation amplifier may be only one part of the total system demand. Confirm the operating supply against the 2.2 V to 36 V range and verify output headroom at the selected gain.
Keep differential input traces short, symmetric, and away from switching nodes and high-current return paths. Place input filtering components close to the relevant amplifier pins, and use a clean analog ground strategy that avoids sharing high-current return paths with the sensor signal. Because the INA122U is intended for accurate differential acquisition, PCB leakage and contamination can matter when the sensor voltage is small.
Do not select the external gain network from nominal gain alone. Check the input common-mode voltage, output swing, sensor excitation, resistor tolerance, and ADC input range together. The INA122U's common-mode range extends to (V−) − 0.1 V, but system transients and protection networks can change the voltage seen by the input. Validate the worst-case operating condition rather than only the nominal signal.
Use a compact analog layout with the INA122U positioned near the sensor input or gain-setting components. Provide a stable, low-impedance supply connection and place decoupling capacitors close to the supply pins according to the manufacturer recommendations. Avoid long copper paths around high-impedance input nodes, because leakage and surface contamination can degrade the accuracy expected from a precision instrumentation amplifier.
合规信息
The supplied source data does not state RoHS, REACH, lead-free, halogen-free, conflict-minerals, or automotive qualification status. These values remain unknown rather than being inferred from the manufacturer name or package.
