INA149AID - ±275V Difference Amplifier | Texas Instruments
料号： INA149AID ✓ 量产中INA149AID 概述
A high common-mode difference amplifier is an instrumentation amplifier that preserves a small voltage difference between two inputs even when both inputs are elevated far beyond the amplifier's supply rails. This capability is essential in power-system monitoring, motor-control systems, test equipment, and industrial measurement circuits where a useful sensor signal may sit on top of a substantially larger voltage. The INA149AID sits within the hierarchy of difference amplifier, instrumentation amplifier, analog signal-conditioning IC, and power-management measurement component.
The main differentiating specifications are the ±275 V common-mode range, unity differential gain, and a verified minimum CMRR of 90 dB under a +125°C DC condition. Common-mode rejection is important because unwanted voltage shared by both inputs should not appear at the output as differential error. The integrated thin-film resistor network provides a defined unity-gain relationship, simplifying circuit design where external gain-setting resistors would otherwise be required.
Internally, the INA149 is a single monolithic device combining a precision op amp with the resistor network. Its high-voltage input structure allows measurement of millivolt-level differential signals in the presence of very large common-mode voltages. That architecture supports direct sensing without an external high-voltage instrumentation front end. The operating range of -40°C to +125°C supports use across industrial environments where temperature variation and long operating lifetimes are important design constraints.
Typical applications include power-rail and inverter monitoring, motor-drive feedback, battery-management measurement, laboratory instrumentation, and high-side sensing in industrial control systems. In each case, the central design trade-off is the need to preserve differential accuracy while controlling errors caused by common-mode voltage, input offset, bandwidth, and supply performance. System designers should also account for the amplifier's power dissipation and the limitations of its package when operating near the upper temperature limit.
Place the INA149AID close to the sensing nodes and maintain short, guarded differential traces to minimize pickup from adjacent switching circuits. A solid ground-plane layout, careful bypassing of the supply pins, and isolation from high-current return paths help preserve measurement quality. Because the exact signal bandwidth and input-offset limits depend on the complete INA149 grade and operating conditions, use the manufacturer datasheet's full electrical tables when sizing filters and setting measurement-error budgets.
This page combines the verified INA149AID specifications, same-footprint alternatives, application guidance, comparison parameters, and practical design notes into an engineering-focused overview. It is intended to help buyers identify the correct amplifier family, confirm packaging, and plan the mechanical, thermal, and signal-integrity requirements of a high common-mode measurement circuit.
直接替换替代料： INA149AID ——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： INA149AID （相同外形与封装尺寸） ——差异在于 Package, Operating Temperature Range, Product Type, Architecture, Bandwidth.
INA149AIDR
✅ 直接替换📋 参考替代料（不在目录中）
INA149-EP
✅ 直接替换📋 参考替代料（不在目录中）
INA117KU/2K5
✅ 直接替换联系询价
查看数据手册 →INA148UA
✅ 直接替换联系询价
查看数据手册 →INA148-Q1
✅ 直接替换📋 参考替代料（不在目录中）
INA149AID 最大额定值与电气特性
| Product Type | High common-mode voltage difference amplifier |
| Amplifier Circuit Count | 1 circuit |
| Architecture | Monolithic precision op amp with integrated thin-film resistor network |
| Differential Gain | 1 V/V (unity gain) |
| Input Common-Mode Voltage Range | -275 V to +275 V |
| Supply Voltage Range | Up to 36 V total, including ±18 V dual supply operation |
| Common-Mode Rejection Ratio | 90 dB minimum at +125°C DC |
| 工作温度范围 | -40°C to +125°C |
| 封装 | 8-pin SOIC |
| 引脚数量 | 8 pins |
| 安装类型 | Surface mount |
| Lead-Free Status | Lead free |
| RoHS 状态 | RoHS compliant |
INA149AID 8-pin soic 引脚配置指南
INA149AID（8-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： INA149AID.
请参阅 数据手册 以查看完整引脚配置。
典型应用
INA149AID 适用于 6 应用s: High-Voltage Power-Rail Monitoring, Motor-Drive Feedback Measurement, Battery-Pack Voltage Balancing, Laboratory Differential Instrumentation, Industrial Sensor Interfacing, Inverter and Converter Feedback.
High-Voltage Power-Rail Monitoring
The INA149AID is well suited to sensing a small voltage difference across a high-side shunt or sense element in an industrial power rail. Its ±275 V common-mode range allows the two inputs to remain elevated while the measured differential voltage stays within the amplifier's linear operating region. The integrated unity-gain resistor network simplifies the signal path, and the verified 90 dB minimum CMRR at +125°C DC helps suppress voltage shared by both inputs. Layout should keep the sense traces short and away from switching nodes so that parasitic pickup does not obscure the differential result.
推荐
Motor-Drive Feedback Measurement
The INA149AID can monitor feedback signals in motor-control and power-converter systems where switching nodes create large common-mode transients. Its ±275 V input common-mode capability is the principal fit because the desired feedback voltage may be small relative to the motor-bus voltage. Unity gain provides a predictable measurement ratio, while the integrated thin-film network removes external gain-setting components. Designers should still verify bandwidth against the switching transient spectrum, provide local supply bypassing, and isolate the sense pair from high-current motor-return paths to preserve differential accuracy.
推荐
Battery-Pack Voltage Balancing
In battery-management systems, the INA149AID can detect the small difference between adjacent cell or group voltages when the common-mode level is much higher than the imbalance being measured. The ±275 V common-mode range provides margin for elevated pack buses, and unity gain supports direct comparison with a controller ADC. The -40°C to +125°C operating range suits demanding industrial environments. Critical design work remains in confirming absolute input limits, control-loop bandwidth, and thermal behavior under the exact battery chemistry and series count.
推荐
Laboratory Differential Instrumentation
The INA149AID is useful in laboratory and field-test equipment that must measure small differential voltages superposed on large common-mode potentials. Its precision unity-gain topology, ±275 V common-mode range, and integrated thin-film network provide a straightforward front end for precision measurement. The verified minimum CMRR of 90 dB at +125°C DC supports stable operation across the extended -40°C to +125°C range. For instrumentation-grade results, evaluate offset and gain error at the actual temperature, control input capacitance, and separate sensitive sense wiring from test-bench power paths.
推荐
Industrial Sensor Interfacing
The INA149AID can serve as the high-voltage interface between an industrial sensor and low-voltage measurement circuitry when the sensor outputs a small differential signal on an elevated common-mode voltage. The ±275 V common-mode range allows the amplifier to reject the large shared voltage while preserving the differential information. Its unity gain and integrated resistor network reduce analog-board complexity, and its wide temperature specification supports harsh environments. Confirm the sensor's output bandwidth and grounding method, and place the amplifier close to the sensor connector to minimize noise pickup before cable faults are assumed absent.
推荐
Inverter and Converter Feedback
The INA149AID supports feedback and fault-detection circuits in inverters, converters, and power-control equipment where a bridge or switching node establishes a large common-mode level. The ±275 V range allows direct sensing of low-level differential information without moving it to a lower voltage first, while unity gain keeps the signal chain predictable. The 90 dB minimum CMRR at +125°C DC is particularly valuable when all sensing nodes move together but the measurement depends only on their difference. Validate surge margins, input bias effects, and bandwidth, and provide clean local bypassing to avoid measurement disturbance.
推荐
推荐产品汇总
工程参考数据： INA149AID ——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 | INA149AIDR | INA149-EP | INA117 | INA148 | INA148-Q1 |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC |
| Product Type | High common-mode voltage difference amplifier | INA149 difference amplifier | INA149 difference amplifier | High common-mode voltage amplifier | High common-mode voltage amplifier | INA148 high common-mode voltage amplifier |
关键差异点
- Highest verified common-mode capability in the INA comparison set （对比 INA148)
- Drop-in ordering flexibility without changing the PCB footprint （对比 INA149AIDR)
- Manufacturer-confirmed compatibility with established high common-mode amplifier families （对比 INA117)
- Extended industrial temperature coverage with high common-mode rejection （对比 INA148-Q1)
设计说明
Route the two sensing inputs as a tightly coupled differential pair. Keep their separation small and continuous from the measurement point to the INA149AID, and avoid routing them alongside power-switching nodes or high-current return paths. A solid ground plane helps provide a low-impedance return, but the differential signal should still be treated as a pair; excessive distance between input traces can allow different noise voltages to appear on the two lines and reduce common-mode rejection.
Place the INA149AID close to the sensing connector or shunt and place its supply bypassing capacitors at the device pins. Keep the input nodes away from the clocking, gate-drive, and switching components that create the common-mode environment being rejected. Because the amplifier is intended to operate with elevated common-mode voltage, its input-network layout and protection components must be evaluated against the actual surge and fault conditions rather than only steady-state voltage.
Verify the complete signal path against the INA149AID bandwidth and the switching spectrum present at the sensing node. A high CMRR does not eliminate errors caused by unequal input capacitance, leakage through protection components, or a common-mode signal that exceeds the relevant device limits. If the measured difference is very small, use matched input components and provide a defined return path; otherwise, parasitic pickup can dominate the useful differential signal.
The INA149AID operates across -40°C to +125°C, but the allowable supply, input, and output conditions must remain within their respective limits over the complete temperature range. At elevated temperature, include the minimum 90 dB CMRR condition at +125°C DC when estimating rejection of a shared input signal. Provide adequate copper around the 8-pin SOIC and avoid placing the device near a localized heat source that could create additional temperature gradients across the board.
合规信息
The INA149AID is identified as lead free and RoHS compliant. The standard INA149AID ordering code is not identified as an automotive-qualified grade. REACH, halogen-free, and conflict-minerals status are not established for this ordering code.