INA125U - Precision Bridge Amplifier, 10V Ref | Texas Instruments
料号： INA125U ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
INA125U 概述
An instrumentation amplifier is a specialized differential amplifier designed for sensors whose useful output is small and appears across two input terminals. Its internal architecture provides high input impedance, accurate differential gain, and strong common-mode rejection. The INA125 adds a precision reference output, allowing a bridge circuit to be excited and its output measured relative to a stable midpoint.
The INA125U offers a 2.7V to 36V supply range, low 460µA quiescent current, maximum 250µV input offset voltage, maximum 2µV/°C offset drift, and a sleep mode. A single external resistor sets the gain, while the integrated amplifier can provide 150kHz bandwidth according to the retrieved product data. These features balance precision, power consumption, and measurement speed for portable and industrial instrumentation.
Electrically, the device is intended for bridge outputs and other low-level differential sources. Input common-mode range, reference accuracy, gain error, and maximum input voltage must be checked against the actual bridge excitation and sensor output. The SOIC package also requires careful attention to ground return paths and supply decoupling when low-level signals are measured.
Typical uses include quarter-bridge and full-bridge strain sensors, load-cell front ends, pressure and force measurement, biomedical instrumentation, industrial process controls, and precision data-acquisition systems. The 10V reference can simplify excitation when the sensor and measurement chain require a defined bridge supply.
The most important design consideration is preserving common-mode and differential signal integrity. Place input and reference grounding deliberately, use low-noise supply bypass capacitors, and verify that the selected gain resistor stays within its recommended range. This page combines verified manufacturer and distributor information with practical application guidance and explicit data gaps rather than estimating unprovided specifications.
直接替换替代料： INA125U ——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： INA125U （相同外形与封装尺寸） ——差异在于 Package, Product Type, Supply Voltage Range, Gain Range, Input Offset Voltage.
快速对比工具——选择替代料号进行并排对比：
INA125UA/2K5
✅ 直接替换📋 参考替代料（不在目录中）
INA125P
✅ 直接替换✓ 有现货
联系询价
查看数据手册 →INA333AIDGKR
✅ 直接替换✓ 有现货
$0.8373 / 个
查看数据手册 →AD623ANZ
✅ 直接替换✓ 有现货
联系询价
查看数据手册 →ADG1411YCPZ-REEL7
✅ 直接替换✓ 有现货
$4.65 / 个
查看数据手册 →INA125U 最大额定值与电气特性
| Product Type | Instrumentation amplifier with precision voltage reference |
| Channel Count | 1 circuit |
| Supply Voltage Range | 2.7 V to 36 V |
| Maximum Supply Voltage | 36 V |
| Gain Range | 4 V/V to 10,000 V/V |
| Gain Setting | Single external resistor |
| 静态电流 | 460 µA |
| Input Offset Voltage | 250 µV maximum |
| Input Offset Drift | 2 µV/°C maximum |
| Voltage Reference | 10 V |
| Bandwidth | 150 kHz |
| Noise at 1kHz | 38 nV/√Hz typical |
| Sleep Mode | Yes |
| 封装 | 16-pin SOIC |
| 安装类型 | Surface mount |
INA125U 16-pin soic 引脚配置指南
INA125U（16-pin 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： INA125U.
请参阅 数据手册 以查看完整引脚配置。
典型应用
INA125U 适用于 6 应用s: Strain-Gauge Load-Cell Front End, Pressure and Force Transducer Signal Chain, Battery-Powered Portable Measurement, Industrial Process-Control Instrumentation, Biomedical and Diagnostic Instrumentation, Precision Data-Acquisition Systems.
Strain-Gauge Load-Cell Front End
The INA125U fits a bridge-sensor front end because it combines differential instrumentation amplification with a precision 10V reference and programmable gain from 4 V/V to 10,000 V/V. A quarter-bridge or full-bridge strain gauge can therefore be excited and amplified without relying on a separate reference block. Keep the sensor excitation below its allowable power and verify the amplifier’s common-mode range at the selected bridge excitation. The 250µV maximum offset and 460µA quiescent current are useful for portable measurement systems, while the SOIC package supports compact analog boards.
推荐
Pressure and Force Transducer Signal Chain
The INA125U is appropriate for piezoresistive pressure, force, and displacement transducers that produce a small differential bridge signal. Its 10V reference provides a defined measurement reference, while the broad 4-to-10,000 gain range lets the designer match amplification to the transducer sensitivity and expected full-scale output. The key design trade-off is common-mode headroom: the bridge output must remain inside the device’s permitted input range, and the selected gain must leave sufficient output swing. Offset calibration should be performed after warm-up for high-resolution measurements.
推荐
Battery-Powered Portable Measurement
The INA125U’s 460µA quiescent current and sleep mode make it suitable for portable, handheld, or remote measurement systems where continuous instrumentation-amplifier consumption matters. Its integrated bridge excitation and reference can reduce the number of external active components in a compact sensor module. The design must still account for sensor self-heating, battery supply variation, reference noise, and the amplifier’s startup behavior when entering or leaving sleep mode. Use low-leakage switches and careful grounding if the sensor must remain connected while the amplifier is disabled.
推荐
Industrial Process-Control Instrumentation
The INA125U can be used in industrial measurement modules when a bridge sensor is several millivolts above or below a system ground and requires accurate differential amplification. Its precision reference, programmable gain, and low offset support repeatable sensor conditioning, while the 2.7V-to-36V supply range allows operation from low-voltage rails to higher-voltage instrumentation systems. Industrial protection components and isolation may be required around sensor wiring. Validate the common-mode range, transient immunity, grounding strategy, and thermal conditions for the final enclosure and cable environment.
推荐
Biomedical and Diagnostic Instrumentation
The INA125U can serve as a low-level analog front end in biomedical and diagnostic instruments when the sensor interface is compatible with its supply, common-mode, and precision characteristics. Its low quiescent current supports power-constrained equipment, and the integrated reference can simplify controlled excitation for suitable resistive bridges. Biomedical designs require careful isolation, patient protection, leakage current analysis, and compliance validation beyond the component datasheet. The amplifier should not be assumed suitable for direct patient-connected use without the complete system safety and application review.
推荐
Precision Data-Acquisition Systems
The INA125U is useful in precision data-acquisition systems that need to resolve a differential bridge signal before conversion by an ADC. Its 250µV maximum offset, 2µV/°C maximum offset drift, and programmable gain provide a defined starting point for front-end sensitivity and stability. The 150kHz bandwidth figure should be checked against the selected gain and the required sensor response time. Place the amplifier close to the sensor or bridge input, use a quiet ground plane, and isolate high-current return paths from the differential measurement node.
推荐
推荐产品汇总
工程参考数据： INA125U ——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 | INA125UA/2K5 | INA125P | INA333AIDGKR | AD623ANZ | ADG141 |
|---|---|---|---|---|---|---|
| Package | 16-pin SOIC | 16-pin SOIC family variant; exact package confirmation required | 16-pin SOIC; package family indicated by comparison result | VQFN-16; not a physical SOIC replacement | SOIC-8; not a physical 16-SOIC replacement | SOIC-8; not a physical 16-SOIC replacement |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices | Analog Devices |
| Special Function | Bridge excitation and sleep mode | INA125-family variant; exact functions require confirmation | INA125-family variant; exact functions require confirmation | Instrumentation amplifier; reference and bridge functions require confirmation | Instrumentation amplifier; reference function require confirmation | Instrumentation amplifier; reference function require confirmation |
关键差异点
- Integrated precision reference and bridge excitation （对比 AD623ANZ)
- Broad programmable gain range （对比 ADG141)
- Low quiescent current for portable systems （对比 INA125P)
设计说明
The INA125U operates from 2.7V to 36V, but the bridge excitation and sensor safe power must remain within their own limits. Because the integrated reference is specified as 10V, do not assume that a 10V excitation is always safe for every load cell or pressure sensor. Check the sensor resistance and power dissipation before connecting the reference, and provide stable local supply bypassing. Estimated: power dissipated in a resistive bridge is VEXC²/Rbridge; for example, a 350Ω bridge at 10V would dissipate about 0.286W, so the sensor’s permitted dissipation must be verified before applying the reference.
Route the two bridge-sensor differential inputs as a matched, short pair and keep them away from switching-node copper and high-current return paths. Place input, supply, and reference bypass components close to their associated pins. The measured bridge node is sensitive to ground gradients, so a clean analog ground and a controlled star return can be more valuable than an elaborate filter. Verify the SOIC land pattern against the exact package drawing and confirm pin names from the manufacturer datasheet before release.
Do not select the gain resistor or output range from nominal gain alone. First confirm that the bridge output stays within the input common-mode range at the selected excitation, then confirm that the amplified signal does not clip the output. Offset voltage and drift also become more important as gain increases. The verified data supplies a 250µV maximum offset and 2µV/°C maximum drift, but it does not provide gain-error, common-mode-rejection, slew-rate, or complete temperature data; obtain those values before making precision claims.
The listed 150kHz bandwidth is a useful orientation point, but usable bandwidth can change with gain and internal compensation. For dynamic bridge measurements, verify the manufacturer’s frequency-response and settling requirements at the selected gain. Add calibration at system level, maintain consistent sensor and reference grounding, and avoid long unshielded sensor cables where noise or common-mode pickup can dominate the bridge signal. Sleep-mode timing should also be measured because startup delay can affect repeated low-energy measurements.
合规信息
The verified manufacturer and distributor results do not provide explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statements for INA125U. The component is not identified as an automotive-qualified part in the supplied data.
