INA126U - 36V Micropower Instrumentation Amp | Texas Instruments
料号： INA126U ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $5.1904 | $5.19 |
| 10 | $5.1904 | $51.90 |
| 100 | $5.1904 | $519.04 |
| 500 | $5.1904 | $2,595.20 |
| 1,000 | $5.1904 | $5,190.40 |
INA126U 概述
An instrumentation amplifier is a specialized amplifier and the final member of the signal-chain hierarchy: sensor output → differential input → instrumentation amplifier → ADC or measurement system. Unlike a general-purpose operational amplifier, an instrumentation amplifier internally supports high input impedance and accurate differential gain, reducing errors when both inputs originate from balanced sensors, resistive bridges, or shunt measurements. The INA126 family uses a two-op-amp architecture optimized for precision and micropower operation.
Verified headline features include a 36 V maximum supply, 175 µA per-channel quiescent current, and 250 µV offset. The manufacturer describes the device for accurate, low-noise differential-signal acquisition across a wide operating voltage range of ±1.35 V to ±18 V. These properties suit portable instruments and low-power acquisition systems where battery energy is limited but input-referred accuracy remains important. The single amplifier in the INA126U also avoids the extra power and board area associated with an unnecessary dual channel.
The INA126U can be configured through an external gain-setting resistor. Because its instrumentation-amplifier architecture rejects common-mode signals before they reach the output, it is particularly useful when the wanted differential signal is much smaller than the voltage shared by both inputs. Designers must still verify input and output common-mode limits, maximum differential input voltage, gain-bandwidth behavior, resistor tolerance, output swing, and the sensor output range for the intended supply voltage. Precision performance ultimately depends on resistor matching and careful grounding as well as the amplifier itself.
Typical uses include battery-powered sensor interfaces, portable measurement instruments, current-shunt amplifiers, bridge-signal conditioning, and low-power data-acquisition front ends. The 175 µA per-channel quiescent current is particularly useful where idle current directly affects battery life. The 250 µV offset specification gives designers a defined input-referred error reference, while the 36 V supply capability supports higher-voltage industrial systems when the individual input and output ranges are observed.
For PCB implementation, keep the external gain resistor close to the gain-setting pins, use a stable low-noise reference plane, and place input-protection capacitance only after checking its effect on bandwidth and transient response. Avoid long parallel input traces, maintain symmetric routing where practical, and provide local supply bypassing. Verify common-mode headroom at worst-case sensor voltage and load current rather than relying only on nominal supply conditions.
This page combines verified manufacturer facts, distributor pricing, same-package alternatives, and application-oriented design guidance. It also distinguishes documented values from parameters requiring confirmation from the complete manufacturer datasheet, helping engineers move from component selection to a defensible low-power sensor-board design.
直接替换替代料： INA126U ——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： INA126U （相同外形与封装尺寸） ——差异在于 Architecture, Mounting Type, Package, Quiescent Current.
快速对比工具——选择替代料号进行并排对比：
INA126UA
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
INA126UA/2K5
✅ 直接替换📋 参考替代料（不在目录中）
INA126U 最大额定值与电气特性
| Device Type | Single-circuit micropower precision instrumentation amplifier |
| Maximum Total Supply Voltage | 36 V |
| Operating Supply Range | ±1.35 V to ±18 V |
| 静态电流 | 175 µA per channel |
| Offset Voltage | 250 µV |
| Architecture | Two-op-amp design |
| Circuit Count | 1 amplifier |
| Signal Type | Differential signal acquisition |
| Gain Configuration | External gain-setting resistor |
| 封装 | 8-pin SOIC, 3.90 mm width |
| 安装类型 | Surface mount |
INA126U 8-pin soic, 3.90 mm width 引脚配置指南
INA126U（8-pin soic, 3.90 mm width 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： INA126U.
请参阅 数据手册 以查看完整引脚配置。
典型应用
INA126U 适用于 6 应用s: Battery-Powered Sensor Front End, Current-Shunt Measurement, Portable Measurement Instrument, Bridge Signal Conditioning, Low-Power Data Acquisition, Process and Control Monitoring.
Battery-Powered Sensor Front End
The INA126U fits a battery-powered sensor interface because its documented quiescent current is 175 µA per channel, while its differential architecture measures the difference between two sensor nodes instead of relying on a single grounded signal. Place it between a bridge or differential sensor and a low-power ADC, using the external gain-setting component specified by the manufacturer. This reduces idle current compared with a conventional higher-power amplifier and limits the energy consumed while the sensor remains connected. The tradeoff is that the sensor and amplifier must remain inside the input common-mode range and preserve adequate output headroom at the selected gain.
推荐
Current-Shunt Measurement
The INA126U is suitable for measuring the small voltage generated across a current shunt while rejecting voltage shared by the shunt and analog return. Its documented 250 µV offset gives the design a defined input-referred error target, and its differential input supports compact sensing layouts. Connect the shunt terminals to the amplifier inputs, select a manufacturer-supported gain, and verify that the maximum shunt voltage cannot violate the differential-input or common-mode limits. Kelvin routing is preferable when trace resistance would otherwise become part of the measurement.
推荐
Portable Measurement Instrument
A handheld meter benefits from the INA126U's 175 µA per-channel quiescent current because amplifier idle power directly affects battery life between readings. The device accepts a documented supply range from ±1.35 V to ±18 V, allowing use in both compact low-voltage systems and higher-voltage instruments. It can condition a differential sensor before conversion by an ADC, but the engineer must account for gain error, resistor tolerance, offset, and output swing. Power-gating strategies should preserve reference and sensor stability rather than repeatedly reconfiguring an unsettled analog node.
推荐
Bridge Signal Conditioning
The INA126U fits resistive-bridge conditioning because differential excitation produces a wanted bridge imbalance on top of a larger common-mode voltage. The instrumentation-amplifier configuration is intended to reduce common-mode influence while preserving weak sensor information, and its 250 µV offset specification helps define baseline error. Set gain with the supported external resistor and ensure both bridge outputs and the final output stay within their respective ranges. For high-accuracy systems, account for bridge tolerance, reference error, amplifier offset, and PCB leakage rather than relying on nominal gain alone.
推荐
Low-Power Data Acquisition
The INA126U can serve as the analog input stage in a compact data-acquisition system because its 175 µA per-channel quiescent current complements low-power conversion and processing. Use the device to amplify differential sensor outputs before an ADC, with the gain chosen from the manufacturer-supported network and the output adjusted to the converter's input range. The 36 V supply ceiling broadens industrial applicability, although transient protection and common-mode limits remain mandatory. For multiplexed systems, settling after channel switching must be included in the acquisition timing budget.
推荐
Process and Control Monitoring
The INA126U is applicable to process monitoring when a sensor produces a differential signal over a common-mode industrial voltage. Its 36 V maximum supply and micropower operation support compact analog modules, while the 250 µV offset specification provides a useful starting point for error analysis. Buffer the sensor if its output impedance is too high, protect inputs against industrial transients, and confirm output drive into the receiving ADC or controller. Watchdog and power-management circuits should not disturb the common reference used by the differential measurement.
推荐
推荐产品汇总
工程参考数据： INA126U ——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 | INA126UA | INA126UA/2K5 |
|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-pin SOIC | 8-SOIC, package details require confirmation | 8-SOIC family ordering option, dimensions require confirmation |
| Circuit Count | 1 instrumentation amplifier | 1 instrumentation amplifier | 1 instrumentation amplifier |
| Architecture | Two-op-amp design | Two-op-amp INA126-family design | Two-op-amp INA126-family design |
| Replacement Evidence | INA126U ordering code | Related family ordering code | TI-recommended replacement for obsolete INA126PA |
关键差异点
- Documented micropower operation （对比 INA126UA/2K5)
- Verified 36 V supply rating （对比 INA126UA)
- Defined precision offset （对比 INA126UA)
设计说明
Do not treat the 36 V maximum supply rating as permission for any input voltage. At every design point, verify the individual input common-mode range, maximum differential input voltage, output swing, and supply limits from the manufacturer datasheet. This matters especially in bridge and industrial systems, where the sensor output can rise above ground while the amplifier still operates from a single low supply.
Route the differential pair as a compact, symmetric path and keep the external gain-setting component close to its specified terminals. Longer input traces add leakage, capacitance, and susceptibility to differences between the two channels. Use a continuous ground reference, minimize switching-current loops beneath the amplifier, and place supply bypassing at the device according to the datasheet layout recommendation.
Estimated: amplifier supply consumption at 5.0 V is approximately 0.875 mA using the documented 175 µA per-channel quiescent current. This is only the unloaded quiescent estimate; external sensor current, gain-network current, leakage, and subsequent circuit loads increase total consumption. In battery designs, include the ADC, references, interface, and sensor loads when calculating operating life.
Input protection, anti-alias filtering, and cable capacitance can alter settling time and usable bandwidth. Add capacitance only after checking the complete datasheet gain-frequency and stability data. For multiplexed sensor inputs, allow the differential pair and gain node to settle after each switch event, and include that interval in the ADC acquisition timing rather than assuming instantaneous channel changes.
合规信息
The supplied verified data does not state compliance for the exact INA126U ordering code. Related-variant comparison pages were not treated as evidence of INA126U compliance.
