INA129PG4 Precision Instrumentation Amplifier | Texas Instruments
料号： INA129PG4 ✓ 量产中INA129PG4 概述
An instrumentation amplifier is a specialized amplifier category designed to amplify the difference between two input signals while rejecting common-mode voltage. The instrumentation-amplifier hierarchy includes differential amplifiers, analog signal-conditioning ICs, amplifiers, and semiconductor devices. Its three-op-amp architecture and current-feedback input stage make it suitable for sensors and measurement systems in which small differential signals are superimposed on a larger common-mode voltage.
Key characteristics include 4 V/µs slew rate, low offset drift of 0.5 µV/5°C maximum, and input protection to +40 V. The wide supply range extends to +18 V, while the input architecture retains a bandwidth of 200 kHz at a gain of 100. These characteristics support precision bridge, current-shunt, and sensor-amplification circuits without requiring a high-power amplifier.
The INA129PG4 uses a versatile three-op-amp architecture. A single external resistor establishes the gain, allowing the same device to serve multiple measurement ranges. Its current-feedback input circuitry is designed to preserve usable bandwidth at higher closed-loop gains. The combination of low supply current, low offset, high CMRR, and protected inputs makes it especially useful for compact, low-power measurement instruments.
Typical applications include bridge-sensor signal conditioning, portable instrumentation, industrial process monitoring, medical measurement interfaces, and low-level differential-signal acquisition. Its protected inputs can simplify front-end design when the source may produce transient overvoltage, although the complete application must still satisfy the device's absolute maximum ratings.
For a new PCB, use the manufacturer pin-description table to assign all eight DIP connections and place the gain resistor close to the gain-setting pin. Check supply voltage, common-mode input range, input impedance, and output swing at the intended gain before finalizing component values.
This product page combines the manufacturer specifications, package details, replacement analysis, parameter comparisons, and practical design guidance to help engineers evaluate the INA129PG4 before committing a precision measurement circuit to production.
直接替换替代料： INA129PG4 ——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： INA129PG4 （相同外形与封装尺寸） ——差异在于 Architecture, Input Protection, Package, Maximum Offset Drift, Maximum Offset Voltage.
INA129PG4 最大额定值与电气特性
| Amplifier Type | Instrumentation amplifier |
| Number of Circuits | 1 circuit |
| 封装 | 8-PDIP (0.300 inch, 7.62 mm pitch) |
| Packaging | Tube |
| Gain-Bandwidth Product | 1.3 MHz |
| Bandwidth at Gain 100 | 200 kHz |
| Slew Rate | 4 V/µs |
| 电源电流 | 700 µA |
| Maximum Supply Voltage | +18 V |
| Maximum Offset Voltage | 50 µV |
| Maximum Offset Drift | 0.5 µV/5°C |
| Maximum Input Bias Current | 5 nA |
| Minimum Common-Mode Rejection | 120 dB |
| Maximum Protected Input Voltage | +40 V |
| Input Protection | Protected to +40 V |
| Architecture | Three-op-amp instrumentation amplifier with current-feedback input circuitry |
| 安装类型 | Through-hole DIP |
INA129PG4 8-pdip (0.300 inch, 7.62 mm pitch) 引脚配置指南
INA129PG4（8-pdip (0.300 inch, 7.62 mm pitch) 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： INA129PG4.
请参阅 数据手册 以查看完整引脚配置。
典型应用
INA129PG4 适用于 6 应用s: Bridge Sensor Signal Conditioning, Portable Medical Instrumentation, Industrial Process Measurement, Current-Shunt Monitoring, Low-Level Data Acquisition, Environmental Sensor Interface.
Bridge Sensor Signal Conditioning
The INA129PG4 fits bridge-based pressure, strain, and force measurements where the useful signal is small and differential. Its 120 dB minimum common-mode rejection helps separate the bridge differential from the common-mode voltage present at both inputs, while 50 µV maximum offset voltage limits error near the output null. A single external resistor sets the gain, allowing the design to be adapted across different bridge sensitivities. The 4 V/µs slew rate also supports dynamic measurements better than a slow precision-only amplifier. Verify the bridge excitation voltage, input common-mode range, output swing, and gain before committing the circuit.
推荐
Portable Medical Instrumentation
The INA129PG4 is suitable for low-level biomedical measurement front ends that require good common-mode rejection and low offset error. Its 700 µA supply current supports compact, battery-operated equipment, while the 5 nA maximum input bias current is favorable for high-impedance sensor interfaces. The protected inputs extend to +40 V, adding useful transient tolerance when connected to patient-connected or externally routed circuitry. Signal-chain safety and applicable medical-device requirements remain system-level responsibilities. The designer should verify input bias behavior, common-mode limits, output range, and noise performance for the selected gain and bandwidth.
推荐
Industrial Process Measurement
The INA129PG4 can condition low-level differential process signals where long sensor wiring may introduce substantial common-mode voltage. Its 120 dB minimum CMRR improves rejection of that shared voltage, and the 1.3 MHz gain-bandwidth product gives adequate bandwidth for many sensor and control-loop signals. The three-op-amp architecture supports simple gain selection with one external resistor. For industrial deployment, verify the available input common-mode range, supply voltage, output swing, and behavior during sensor faults. The +40 V input protection rating can simplify transient handling, although protection should not be treated as a substitute for proper surge-protection design.
推荐
Current-Shunt Monitoring
The INA129PG4 is appropriate for measuring the small voltage generated across a current shunt in power-conversion and battery systems. Its low 50 µV maximum offset voltage improves measurement resolution near zero current, and 120 dB minimum CMRR rejects supply ripple or switching-node voltage common to both shunt terminals. A single gain-setting resistor simplifies adaptation across different shunt ranges. Designers must confirm that the shunt voltage stays within the input common-mode range and that the amplifier output remains within its swing limits at maximum load current. Input filtering and Kelvin routing are important for accurate high-current measurements.
推荐
Low-Level Data Acquisition
The INA129PG4 works as the analog front end for low-level data-acquisition channels that require accurate differential sensing without high quiescent power. Its 700 µA supply current, 1.3 MHz gain-bandwidth product, and 4 V/µs slew rate provide a practical balance between precision and responsiveness. The common-mode rejection and low offset reduce errors in thermocouple, strain, and pressure channels. Choose the external gain resistor and decoupling network from the manufacturer application guidance, and confirm that the selected gain does not force the output outside its allowable swing. Place the gain resistor close to the device to reduce susceptibility to pickup and board contamination.
推荐
Environmental Sensor Interface
The INA129PG4 is suitable for environmental sensors that present a small differential output over a larger common-mode voltage, including resistive and bridge-based sensing elements. Its 120 dB minimum CMRR helps maintain measurement accuracy when the sensor is not referenced to ground, and the low 700 µA supply current benefits remote or energy-limited nodes. The 50 µV maximum offset and 5 nA maximum input bias current support low-level signal integrity. Check the sensor excitation scheme, input impedance, common-mode range, and permitted temperature range before deployment. For long cable runs, add appropriate input protection and filtering while retaining low-noise signal paths.
推荐
推荐产品汇总
工程参考数据： INA129PG4 ——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 | INA129P | INA128P |
|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-PDIP | 8-PDIP - same package | 8-PDIP - same package |
| Amplifier Type | Instrumentation amplifier | Instrumentation amplifier | Instrumentation amplifier |
| Number of Circuits | 1 circuit | 1 circuit | 1 circuit |
| Gain-Bandwidth Product | 1.3 MHz | 1.3 MHz | 350 kHz |
| Supply Current | 700 µA | 700 µA | 500 µA |
| Slew Rate | 4 V/µs | 4 V/µs | 2 V/µs |
关键差异点
- Higher gain-bandwidth product than the lower-bandwidth INA12x alternative （对比 INA128P)
- Protected inputs for transient-tolerant measurement interfaces （对比 INA128P)
- Same-package ordering option preserves the original footprint （对比 INA129P)
设计说明
Place the external gain-setting resistor close to the corresponding INA129PG4 pin and route the differential input pair as a matched, compact pair. Keep high-impedance input traces away from switching nodes, inductors, and digital return paths. Use a solid ground reference beneath the analog section and follow the manufacturer layout guidance for bypass-capacitor placement. These steps minimize parasitic pickup, board contamination effects, and gain-error contributions that can be significant in a low-offset amplifier.
Decouple the supply pins with the capacitance and ESR range specified in the manufacturer datasheet, and place the devices physically close to the INA129PG4. The amplifier's stated 700 µA supply current does not include every load presented by the gain resistor and external circuit. Confirm the complete rail voltage and output headroom at the highest input and lowest load conditions. Input protection to +40 V does not permit operation above the device's separate absolute maximum ratings.
Do not select the INA129PG4 using only its 50 µV maximum offset specification. At high closed-loop gain, resistor tolerance, bias-current error, output-range restrictions, and input common-mode limits can dominate total measurement error. Use the manufacturer gain equation to calculate the external resistor, then check the resulting output voltage at both input extremes. For shunts and bridges, use Kelvin routing where available to avoid adding copper and connector resistance to the measured voltage.
合规信息
No definitive compliance declaration was identified in the referenced product and ordering information. The INA129PG4 is an industrial instrumentation amplifier rather than an automotive-qualified device.
