INA131BP - G=100 Instrumentation Amplifier | Texas Instruments
料号： INA131BP ✓ 量产中INA131BP 概述
An instrumentation amplifier is a specialized amplifier that amplifies the voltage difference between two inputs while rejecting common-mode interference. Its internal topology belongs to the amplifier hierarchy: instrumentation amplifier, operational amplifier, analog signal-conditioning IC, and semiconductor. Unlike a conventional differential amplifier, this device is intended to provide accurate differential gain with minimal dependence on external resistor matching.
The INA131BP provides a fixed gain of 100, simplifying circuit design because no external gain-setting network is required for normal operation. Its 70 kHz bandwidth supports signals from slow sensor measurements through moderate-bandwidth industrial and instrumentation signals. The 2.25 V to 18 V operating supply supports single-supply and dual-supply arrangements, while the listed maximum total supply voltage of 50 V provides additional headroom for suitable protection and biasing conditions.
The three-op-amp design is a key technical feature because it performs differential input amplification, common-mode rejection, and level shifting in one integrated circuit. The laser-trimmed construction is intended to improve gain accuracy and reduce the need for calibration. Its 0.7 V/µs slew rate helps the output track input steps without excessive distortion, although bandwidth and slew-rate requirements should both be checked against the intended signal bandwidth.
Typical uses include bridge-transducer signal conditioning, current-shunt measurement, industrial sensor interfaces, laboratory instrumentation, and analog-to-digital converter front ends. The fixed gain is particularly useful when a transducer already includes scaling and the system requires consistent amplification before sampling. The device can also participate in low-side current measurement when the shunt voltage remains within the amplifier's input and common-mode limits.
Designers should verify the input common-mode range, output swing, offset voltage, bias current, noise, and supply-current limits in the INA131 datasheet before finalizing a board. Decoupling capacitors should be placed directly beside the supply pins, and the input and reference connections should be routed away from noisy switching nodes. Because the INA131BP uses a through-hole PDIP package, it is also convenient for prototypes, educational systems, and test equipment where socketed construction or hand assembly is useful.
This page consolidates the confirmed electrical characteristics, package information, practical application guidance, and verified drop-in alternatives for the INA131BP. It is designed to help engineers compare the fixed-gain amplifier with other instrumentation-amplifier options while keeping PCB compatibility, supply range, gain, and bandwidth requirements in view.
直接替换替代料： INA131BP ——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： INA131BP （相同外形与封装尺寸） ——差异在于 Package, Supply Voltage Range, Slew Rate, Amplifier Type, Input Bias Current.
INA126P
✅ 直接替换联系询价
查看数据手册 →INA121UA
✅ 直接替换联系询价
查看数据手册 →INA128P
✅ 直接替换联系询价
查看数据手册 →INA131BP 最大额定值与电气特性
| Amplifier Type | Precision instrumentation amplifier |
| Internal Amplifier Count | 3 amplifiers |
| Nominal Gain | 100 V/V |
| Gain Configuration | Fixed gain |
| Supply Voltage Range | 2.25 V to 18 V |
| Maximum Total Supply Voltage | 50 V |
| Signal Bandwidth | 70 kHz |
| Slew Rate | 0.7 V/µs |
| Adjustment Method | On-chip laser trimming |
| Number of Circuits | 1 circuit |
| Package Type | 8-pin PDIP |
| 引脚数 | 8 pins |
| 安装方式 | Through-hole |
| Temperature Grade | Industrial grade |
INA131BP 引脚配置
| 引脚 1 | RG — Gain-setting resistor connection |
| 引脚 2 | IN- — Inverting input |
| 引脚 3 | IN+ — Non-inverting input |
| 引脚 4 | V- — Negative supply connection |
| 引脚 5 | REF — Reference input |
| 引脚 6 | OUT — Amplified output |
| 引脚 7 | V+ — Positive supply connection |
| 引脚 8 | RG — Gain-setting resistor connection |
典型应用
INA131BP 适用于 6 应用s: Bridge Transducer Signal Conditioning, Low-Side Current-Shunt Measurement, Industrial Sensor Interface, Laboratory Instrumentation Front End, Analog-to-Digital Converter Input Conditioning, Process Control Monitoring.
Bridge Transducer Signal Conditioning
The INA131BP fits bridge-based pressure, load, and strain measurements because its fixed gain of 100 provides a defined conversion from millivolt-level differential outputs to a larger signal for an ADC. According to the Texas Instruments INA131 datasheet, the device has a three-amplifier architecture and a 70 kHz bandwidth. Place the amplifier across the bridge output, maintain a common reference near the sensor midpoint, and verify that bridge excitation and input common-mode voltage stay within the electrical limits.
推荐
Low-Side Current-Shunt Measurement
For low-side shunt sensing, the INA131BP amplifies the small differential voltage produced across a current-sense resistor while rejecting the supply-side common-mode voltage. Its fixed gain of 100 and 70 kHz bandwidth are appropriate for many control and monitoring paths. Keep the shunt close to the amplifier ground reference, route the two differential inputs as a compact pair, and confirm that both common-mode and output swing limits satisfy the actual shunt voltage range.
推荐
Industrial Sensor Interface
The INA131BP is appropriate for industrial sensor interfaces that present a small differential voltage and require repeatable fixed gain. Its 2.25 V to 18 V supply range supports both low-voltage and conventional industrial rails, while the three-op-amp design provides integrated differential amplification and common-mode handling. Place supply-decoupling capacitors beside the device, isolate sensitive input routing from switching nodes, and test offset and output behavior over the intended temperature range.
推荐
Laboratory Instrumentation Front End
The INA131BP can serve as the first analog stage in laboratory instrumentation, converting a low-level differential input into a signal suitable for display, analysis, or digitization. A fixed gain of 100 simplifies calibration when the probe and source produce a predictable output. The 70 kHz bandwidth covers moderate-frequency measurements, but operators should account for the 0.7 V/µs slew rate and verify offset, noise, and input-range characteristics for precision bench work.
推荐
Analog-to-Digital Converter Input Conditioning
The INA131BP conditions small differential sensor outputs before an ADC, using its fixed gain of 100 to increase signal span and improve use of the converter's input range. The 70 kHz bandwidth accommodates many low-to-moderate-bandwidth control and measurement channels, while the 2.25 V minimum supply supports low-voltage systems. The reference and output connections should remain quiet, and the amplifier's settling behavior should be checked against the ADC sampling architecture.
推荐
Process Control Monitoring
The INA131BP is useful in process-control loops where a pressure, force, level, or current sensor produces a low-level differential signal. Its fixed gain of 100 and industrial-grade component designation support a repeatable signal path, while the three-amplifier architecture simplifies implementation compared with a discrete precision differential stage. Designers should verify the complete loop bandwidth, common-mode headroom, and output swing against the controller input range.
推荐
推荐产品汇总
工程参考数据： INA131BP ——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 | INA126 | INA121 | INA128P | INA114 | AD620 |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Package | 8-pin PDIP | 8-pin PDIP | 8-pin PDIP | 8-pin PDIP | 8-pin PDIP | 8-pin PDIP |
| Nominal Gain | 100 V/V | Selectable; supports a 100 V/V configuration | Selectable; supports a 100 V/V configuration | 100 V/V | Selectable; supports a 100 V/V configuration | 100 V/V |
关键差异点
- Fixed-gain implementation simplifies the signal path （对比 INA126)
- Confirmed 70 kHz bandwidth and 0.7 V/µs slew rate （对比 AD620)
- Three-amplifier differential architecture （对比 INA121)
- Single-supply operation starts at 2.25 V （对比 INA128P)
设计说明
Place the supply-decoupling capacitors immediately adjacent to the INA131BP supply pins, with the shortest possible return path to the ground reference. Route IN+ and IN- as a tightly coupled differential pair, keep the reference node away from switching currents, and avoid creating copper paths beneath sensitive input nodes. The 70 kHz bandwidth reduces the need for extreme high-frequency layout work, but proper grounding remains essential for preserving differential accuracy.
Do not treat the fixed gain of 100 as permission to ignore input common-mode limits or output swing. A shunt, bridge, or sensor can generate a common-mode level outside the usable range even when its differential output is small. Before layout release, calculate the worst-case input voltage, reference voltage, and output voltage over supply tolerance, sensor excitation range, and temperature. Use the manufacturer pin description and electrical characteristics tables for final verification.
Account for both the 70 kHz bandwidth and 0.7 V/µs slew rate when designing a signal path. Large input steps can expose slew-rate limits even when their frequency content lies below the small-signal bandwidth. For amplitude-critical measurements, simulate the expected sensor transition, confirm the output remains inside its linear range, and terminate or filter the connection according to the source impedance and cable length.
The normal INA131BP supply range is 2.25 V to 18 V, while the listed maximum total supply voltage is 50 V. Do not use the 50 V figure as an operating point. Establish the positive and negative rails from the system's noise and headroom requirements, and verify the sum of the rail voltages against absolute maximum limits before power-up. This is particularly important when substituting a dual-supply design into a single-supply footprint.
合规信息
The industrial-grade component designation and 8-pin PDIP package are confirmed, but no specific RoHS, REACH, halogen-free, lead-free, conflict-minerals, or automotive qualification statement is identified. Confirm current compliance documents with the manufacturer before release.