INA114AP - 1MHz Precision Instrumentation Amplifier | Texas Instruments
部品番号: INA114AP ✓ 生産中INA114AP 概要
An instrumentation amplifier is a specialized analog amplifier that measures the voltage difference between two inputs while rejecting common-mode voltage and providing controlled gain. The INA114 family belongs to the broader operational amplifier hierarchy as an instrumentation amplifier, precision analog IC, signal-conditioning IC, and power-management-dependent semiconductor device. This makes it suitable for bridge sensors, load cells, thermocouples, current shunts, and other transducers whose useful output occupies only a small portion of the applied voltage.
The key electrical benefits of the INA114AP include a 1 MHz gain-bandwidth product, maximum input offset voltage of 50 µV, maximum offset drift of 0.25 µV/°C, maximum input bias current of 2 nA, and common-mode rejection of at least 115 dB. Its input-noise density is 11 nV/√Hz, making it effective for low-amplitude signals where broadband amplifier noise would otherwise obscure the measurement. Input overvoltage protection extends to ±40 V, while the supply range reaches ±18 V. These characteristics provide useful headroom in industrial and measurement systems where input transients and supply variations must be tolerated.
The three-op-amp instrumentation-amplifier architecture supports accurate differential measurement with adjustable gain. A differential signal applied across the input terminals is amplified relative to ground or the voltage connected to the reference terminal. The gain depends on the external resistor connected to the gain-control pins, allowing the same device family to serve multiple transducer sensitivities. The 1 MHz bandwidth makes it suitable for applications extending beyond static measurement, including moderate-rate sensor acquisition and feedback control.
Typical uses include load-cell and weighing systems, strain-gauge bridges, thermocouple interfaces, industrial pressure and flow sensors, biomedical instrumentation, and current-shunt measurements. The combination of low offset, high common-mode rejection, and low bias current is particularly valuable when the sensor is physically remote or when its leads pick up industrial noise. The 115 dB minimum common-mode rejection helps preserve a small differential signal even when both inputs ride on a larger common-mode voltage.
A successful design must include adequate bypassing, careful routing of the two input paths, and a stable gain resistor. Place the input and supply capacitors close to their associated pins, keep the two input traces symmetrical, and avoid routing sensitive signals beside high-current or switching nodes. Select the gain resistor with suitable tolerance and temperature coefficient, and verify input and output swing against the actual sensor range. When the source impedance is high, account for amplifier bias-current error before interpreting the measured differential voltage.
This page combines manufacturer specifications, exact-source pricing eligibility, package-level pin information, application guidance, and confirmed drop-in alternatives. It also highlights the distinction between a true same-footprint replacement and a merely similar instrumentation amplifier, helping engineers compare parts without relying on an incomplete cross-reference list.
ドロップイン代替品: INA114AP — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: INA114AP （同一形状・フットプリント） — 相違点: Package, Mounting Type, Operating Temperature Range, Architecture, Maximum Input Bias Current.
INA114BU
✅ ドロップイン価格はお問い合わせください
データシートを見る →INA129PA
✅ ドロップイン価格はお問い合わせください
データシートを見る →INA114AP 最大定格＆電気的特性
| Amplifier Type | Precision instrumentation amplifier |
| Number of Circuits | 1 circuit |
| Gain-Bandwidth Product | 1 MHz |
| Maximum Offset Voltage | 50 µV |
| Maximum Offset Voltage Drift | 0.25 µV/°C |
| Input Noise Density | 11 nV/√Hz |
| Maximum Input Bias Current | 2 nA |
| Minimum Common-Mode Rejection | 115 dB |
| Input Overvoltage Protection | ±40 V |
| Supply Voltage Range | ±18 V |
| Maximum Quiescent Current | 3 mA |
| 動作温度範囲 | -40°C to +85°C |
| パッケージ | 8-pin PDIP |
| 実装タイプ | Through-hole |
| Architecture | Three-op-amp instrumentation amplifier |
| Long-Term Stability | Specified as excellent long-term stability |
| Compliance | RoHS and REACH status not stated |
INA114AP ピン構成
| ピン 1 | RG — Gain-control resistor connection |
| ピン 2 | IN- — Inverting input |
| ピン 3 | IN+ — Noninverting input |
| ピン 4 | V- — Negative supply connection |
| ピン 5 | REF — Output reference input |
| ピン 6 | OUT — Amplified output |
| ピン 7 | V+ — Positive supply connection |
| ピン 8 | RG — Gain-control resistor connection |
主な用途
INA114AP の用途: 6 件s: Load-Cell and Weighing Systems, Strain-Gauge Bridge Acquisition, Thermocouple Signal Conditioning, Industrial Pressure and Flow Sensing, Medical and Bioinstrumentation Front Ends, Current-Shunt Measurement.
Load-Cell and Weighing Systems
The INA114AP fits load-cell and weighing systems that convert small differential bridge voltages into a measurable analog signal. Its 50 µV maximum offset voltage and 0.25 µV/°C maximum offset drift reduce errors relative to weak bridge outputs, while 115 dB minimum common-mode rejection helps reject voltage shared by both bridge inputs. Connect the bridge differentially across the input terminals, configure the gain with the external resistor, and provide normal input filtering. The 1 MHz bandwidth supports measurement rates beyond static weighing while remaining broad enough for practical industrial load-cell dynamics.
おすすめ
Strain-Gauge Bridge Acquisition
The INA114AP is appropriate for strain-gauge bridge front ends in which mechanical stress produces a millivolt-level differential output. Its 2 nA maximum input bias current limits current-related error in high-impedance bridges, and its 11 nV/√Hz input noise helps preserve weak signals. Place the amplifier close to the bridge connections, keep both input paths symmetrical, and route the gain resistor away from switching nodes. The 1 MHz bandwidth accommodates dynamic strain signals, but input filtering and settling time should be checked against the mechanical measurement bandwidth.
おすすめ
Thermocouple Signal Conditioning
The INA114AP can condition thermocouple outputs because its low offset voltage, 0.25 µV/°C maximum drift, and 2 nA maximum input bias current are well suited to microvolt-scale differential measurements. Use the reference terminal to establish the output baseline, apply cold-junction compensation at the system level, and install filters that reject mains-related interference without excessive phase delay. Its 1 MHz bandwidth leaves ample bandwidth for common thermocouple response rates, although the actual system accuracy will usually be dominated by thermocouple calibration, wiring, and cold-junction errors.
おすすめ
Industrial Pressure and Flow Sensing
The INA114AP is suitable for pressure transmitters and flow sensors that produce low-level differential signals over substantial common-mode voltage. Its 115 dB minimum common-mode rejection improves signal preservation in electrically noisy industrial environments, while ±40 V input overvoltage protection adds tolerance to wiring transients. Place protection and filtering ahead of the inputs when exposed to external cabling, keep the sensor return path stable, and avoid exceeding the normal common-mode operating limits. The 1 MHz bandwidth supports fast-response pressure and flow systems without requiring a high-speed amplifier architecture.
おすすめ
Medical and Bioinstrumentation Front Ends
The INA114AP can serve as the analog front end for low-level biomedical transducers where offset, bias current, and common-mode noise affect measurement integrity. Its 50 µV maximum offset, 11 nV/√Hz noise density, and high common-mode rejection support accurate amplification of small differential signals. Protect patient-connected inputs with the required isolation and limiting network, and ensure that protection components do not introduce leakage or excessive noise. The device is an instrumentation amplifier rather than a complete medical front end, so system safety, isolation, and electrode-interface requirements remain separate design tasks.
おすすめ
Current-Shunt Measurement
The INA114AP is appropriate for measuring the voltage developed across a current shunt when the resulting differential signal is small and common-mode voltage is significant. Its 2 nA maximum input bias current reduces errors in high-resistance shunt arrangements, and 115 dB minimum common-mode rejection helps preserve accuracy when the shunt sits near a high-voltage or high-current conductor. Route the two shunt connections as a tightly coupled differential pair, keep them away from power-switching nodes, and use the 1 MHz bandwidth to accommodate current transients while applying filtering for the required measurement bandwidth.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: INA114AP — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | INA114BU | INA129PA |
|---|---|---|---|
| Package | 8-pin PDIP | 8-pin PDIP | 8-pin PDIP |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Amplifier Type | Precision instrumentation amplifier | Precision instrumentation amplifier | Instrumentation amplifier |
主な差別化要因
- Lower maximum offset voltage for precision bridge measurements （vs INA129PA)
- Published equivalence supports straightforward substitution （vs INA114BU)
- Input-noise and common-mode performance for weak differential signals （vs INA129PA)
設計ノート
Route the INA114AP input connections as a short, tightly coupled differential pair with comparable geometry and symmetry. Keep the gain resistor close to pins 1 and 8, and place input filtering components near the amplifier rather than at a distant connector. Sensitive input traces should remain away from inductors, switching-regulator outputs, relay contacts, and high-current return paths to minimize differential pickup.
Do not assume that the ±40 V input overvoltage rating permits continuous operation at ±40 V. It describes input protection tolerance, while normal sensing and common-mode limits must remain inside the manufacturer operating conditions. The INA114AP also supports a ±18 V supply range; exceeding that limit or reversing the supply polarity can damage the device.
Choose the gain resistor with adequate tolerance and temperature coefficient for the required measurement accuracy, and follow the manufacturer's gain equation when converting the resistor value to closed-loop gain. Input bias-current error can become significant with high source impedance. For long sensor cables, use suitable input protection and filtering while accounting for the added capacitance, leakage, noise, and settling behavior of those components.
コンプライアンス情報
No definitive RoHS, REACH, lead-free, halogen-free, or conflict-minerals statement was identified for the exact INA114AP ordering suffix. This instrumentation amplifier is not presented as an AEC-Q100-qualified automotive device.