INA149N - ±275V High Common-Mode Difference Amplifier | TI
料号： INA149N ✓ 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 |
INA149N 概述
A difference amplifier is a type of analog signal-conditioning amplifier that measures only the voltage difference between two input nodes while rejecting any voltage common to both. Within the signal-chain hierarchy, it sits between a raw sensor or power-rail node and an ADC, providing level shifting and common-mode rejection. The difference amplifier category belongs to the broader family of instrumentation amplifiers and amplifier ICs in precision analog front ends.
The INA149 is a single, monolithic device consisting of a precision op amp and an integrated, laser-trimmed thin-film resistor network. This integration is the key differentiator: the resistor matching on-chip yields a CMRR and gain accuracy that discrete resistor-op-amp solutions cannot economically match. According to the TI datasheet, the part accurately measures small differential voltages in the presence of common-mode signals up to ±275 V, and its inputs are protected from momentary voltage surges, which matters when probing motor drives, inverters, and industrial power buses.
Architecturally, the thin-film network divides the high common-mode input down into the operating range of the internal precision op amp, allowing safe measurement of shunt voltages and bus voltages that sit hundreds of volts above or below the amplifier supply rails. The unity-gain configuration means the output directly reproduces the differential input, simplifying scaling math in firmware.
Typical applications include high-side and low-side current sensing in motor drives, DC bus voltage monitoring in industrial inverters, battery-management systems, and data-acquisition front ends where measurement nodes must swing far beyond the ADC range.
Design-wise, ensure the reference pin is driven from a low-impedance source, since reference-pin impedance directly degrades CMRR. Layout symmetry of the resistor network inputs preserves accuracy at high common-mode.
This page synthesizes verified distributor data, drop-in alternatives, comparison tables, and practical design notes not found in the manufacturer datasheet alone.
直接替换替代料： INA149N ——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： INA149N （相同外形与封装尺寸） ——差异在于 Operating Temperature Range, Package, Amplifier Type, Gain, Input Protection.
快速对比工具——选择替代料号进行并排对比：
INA149AID
✅ 直接替换📋 参考替代料（不在目录中）
INA149AMDREP
✅ 直接替换📋 参考替代料（不在目录中）
INA117KU/2K5
✅ 直接替换✓ 有现货
$2.55 / 个
查看数据手册 →INA148
✅ 直接替换📋 参考替代料（不在目录中）
AD629ARZ-R7
✅ 直接替换✓ 有现货
$6.18 / 个
查看数据手册 →AD8479
✅ 直接替换📋 参考替代料（不在目录中）
INA149N 最大额定值与电气特性
| Product Type | Precision unity-gain difference amplifier |
| Gain | 1 V/V (unity) |
| Input Common-Mode Voltage Range | ±275 V |
| Number of Channels | 1 |
| Architecture | Precision op amp + integrated thin-film resistor network |
| Input Protection | Protected from momentary voltage surges |
| 封装 | 8-SOIC |
| 工作温度范围 | -40C to +125C |
| 安装类型 | Surface Mount |
| Manufacturer | Texas Instruments |
INA149N 8-soic 引脚配置指南
INA149N（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： INA149N.
请参阅 数据手册 以查看完整引脚配置。
典型应用
INA149N 适用于 6 应用s: High-Side Current Sensing in Motor Drives, Industrial DC Bus Voltage Monitoring, Battery Management Systems, Data Acquisition Front Ends, Power Inverter and Solar Converter Monitoring, Test and Measurement Instrumentation.
High-Side Current Sensing in Motor Drives
The INA149N fits motor-drive high-side current sensing because its ±275 V common-mode range lets it bridge a shunt resistor riding directly on the DC bus, far above the amplifier supply rails, per the TI datasheet. The unity-gain (1 V/V) configuration converts the shunt differential voltage into a ground-referenced single-ended output without firmware scaling math. Placed across the shunt with a low-impedance-driven reference pin, it preserves CMRR; the integrated thin-film resistor network supplies the resistor matching a discrete op-amp solution cannot match economically. The surge-protected inputs absorb momentary bus transients from PWM switching, improving system robustness in industrial drive environments.
推荐
Industrial DC Bus Voltage Monitoring
For DC bus voltage monitoring in industrial inverters and power supplies, the INA149N's up-to-±275 V input common-mode range directly addresses buses that sit hundreds of volts above ground. The monolithic thin-film resistor network divides the high common-mode into the internal precision op amp's operating range, so one SOIC-8 device replaces a multi-component discrete divider-plus-amp chain with better matching and less drift. The unity-gain output feeds an ADC channel directly, and the -40C to +125C extended industrial range covers cabinet temperatures. Designers should drive the reference pin from a low impedance, such as an op-amp buffer, since reference impedance degrades common-mode rejection.
推荐
Battery Management Systems
In battery-management systems, cell-stack and pack-level voltages frequently exceed the ADC range and ride on high common-mode potentials; the INA149N measures these small differential voltages against a ±275 V common-mode background, per the TI datasheet. Its surge-protected inputs withstand momentary transients from contactor switching and load steps typical of battery systems. The unity-gain architecture keeps per-channel accuracy identical and calibration simple, while the integrated thin-film network eliminates external precision resistors that would otherwise dominate error budgets. Operation to +125C supports battery packs in high-temperature enclosures, and the SOIC-8 footprint enables compact per-module sensing circuits.
推荐
Data Acquisition Front Ends
Data-acquisition systems measuring industrial signals benefit from the INA149N as the first stage between a high-common-mode measurement node and an ADC. The ±275 V common-mode tolerance allows direct connection to measurement points that would damage ordinary instrumentation amplifiers, and the unity gain reproduces the differential input with the accuracy set by the laser-trimmed thin-film network. Because the output is single-ended and ground-referenced, any precision ADC can follow without additional level shifting. Input surge protection provides front-line robustness against field transients, reducing channel failure rates in distributed acquisition nodes deployed across factories and energy installations.
推荐
Power Inverter and Solar Converter Monitoring
Solar and grid-tie inverters require continuous measurement of DC-link voltage and current under high common-mode conditions; the INA149N handles this with its ±275 V common-mode range and momentary-surge input protection described in the TI datasheet. The monolithic thin-film resistor network keeps gain and CMRR stable over temperature, which directly affects inverter control-loop accuracy and reporting compliance. Unity gain simplifies scaling from the sense element to the controller ADC. Its extended -40C to +125C operation matches outdoor inverter enclosures, and the standard SOIC-8 footprint supports proven, low-risk layouts in safety-relevant power-conversion designs.
推荐
Test and Measurement Instrumentation
Bench and automated test equipment probing high-voltage nodes needs input protection plus accuracy; the INA149N provides both, measuring small differential signals in the presence of up to ±275 V common-mode with surge-protected inputs, per the TI datasheet. The integrated thin-film network delivers repeatable unity-gain accuracy channel-to-channel, which is critical for calibration stability in instruments. Because the part is pin-compatible with the INA117 and INA148, instrument platforms can migrate to the INA149 for improved performance without layout changes. The SOIC-8 package and -40C to +125C range simplify qualification across instrument operating envelopes.
推荐
推荐产品汇总
工程参考数据： INA149N ——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 | INA149AID | INA149AMDREP | INA117 | AD629 | AD8479 |
|---|---|---|---|---|---|---|
| Package | SOIC-8 | SOIC-8 - same | SOIC-8 - same | SOIC-8 - same | SOIC-8 - same | SOIC-8 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices | Analog Devices |
| Generation / Accuracy | Latest (improved over INA117/INA148) | Latest | Latest (EP grade) | Older generation | Cross-brand equivalent | Cross-brand equivalent |
| Application Grade | Industrial | Industrial | Enhanced product (harsh environment) | Industrial (legacy) | Industrial | Industrial precision |
关键差异点
- Latest-generation accuracy in a legacy-compatible footprint （对比 INA117)
- Improved performance over INA148 （对比 INA148)
- ±275 V common-mode range with monolithic thin-film network （对比 AD629)
设计说明
Drive the INA149 reference (REF) pin from a low-impedance source such as an op-amp buffer. Any resistance in series with the reference corrupts the resistor-network balance and directly degrades common-mode rejection. This is the single most common cause of poor CMRR in difference-amplifier layouts and applies equally when evaluating drop-in substitutes such as INA117, INA148, or AD629 on the same footprint.
Keep the two differential input traces symmetric and equal in length to preserve the matched source impedance seen by the integrated thin-film resistor network. Place the INA149 close to the shunt or measurement tap, and provide a solid ground return for the reference node. Avoid routing high-voltage bus traces under the amplifier to prevent leakage currents from introducing offset errors at the precision inputs.
Treat the ±275 V common-mode rating as a continuous limit and the input surge protection as covering only momentary transients, per the TI datasheet. Do not rely on surge protection for sustained overvoltage. When substituting pin-compatible parts (INA117, INA148, AD629), re-verify error at the actual operating common-mode voltage and frequency, supply and reference conditions, and validate worst-case - as the octatronics cross-reference guidance emphasizes.
合规信息
Compliance data was not present in the verified web data for the INA149N suffix. Consult the TI product page and distributor compliance documents for RoHS/REACH status.
