INA129PA - Precision Low-Power Instrumentation Amplifier | TI
部品番号: INA129PA ✓ 生産中INA129PA 概要
An instrumentation amplifier is a differential analog IC used to amplify the voltage difference between two inputs while rejecting signals common to both inputs. The INA129 belongs to the broader instrumentation-amplifier, amplifier-IC, and analog-semiconductor hierarchy. Its internal gain-setting arrangement supports precise amplification of small differential signals in sensor interfaces, industrial measurement systems, and laboratory equipment.
The verified device features distinguish the INA129 from ordinary general-purpose operational amplifiers. A 50 uV maximum input offset voltage reduces the effect of input-referred mismatch, while the 0.5 uV/degC maximum drift limits offset variation with temperature. Maximum input bias current of 5 nA is especially relevant when the source impedance is high. Minimum CMRR of 120 dB suppresses common-mode interference, and the -40 V to +40 V input protection range helps the interface tolerate larger external voltages than the internal operating range.
The INA129 supports a wide supply range of plus or minus 18 V. A wide operating range allows the amplifier to process signals within systems using higher-voltage rails while retaining the low-power characteristics highlighted for this device. Exact gain, bandwidth, quiescent-current, input-voltage, and output-voltage limits were not available in the supplied verified data and should be taken from the manufacturer datasheet before final design release.
Typical uses include bridge-sensor interfaces, current-shunt measurement, precision data acquisition, industrial process monitoring, and low-level differential signal conditioning. For bridge or shunt circuits, the 120 dB minimum CMRR helps reject common-mode noise, while low offset voltage and drift reduce measurement error. The protected inputs may improve robustness when transients or nearby switching nodes can appear at the input terminals.
Designers should verify the gain equation, external resistor value, permissible input and output swing, and supply-current limits against the current manufacturer datasheet. Input filtering, source-impedance balancing, grounding, and placement near the measured signal are also important because excessive imbalance can degrade CMRR and the low-offset performance expected from this precision device.
This page combines verified manufacturer and distributor information with practical selection guidance, application analysis, pricing context, and verified drop-in alternatives. It distinguishes documented INA129PA characteristics from information that remains unavailable, helping engineers make a more reliable instrumentation-amplifier choice without inventing specifications.
ドロップイン代替品: INA129PA — 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: INA129PA （同一形状・フットプリント） — 相違点: Package, Mounting Type, Architecture, Product Type, Maximum Input Offset Drift.
INA129P
✅ 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 →INA128PAG4
✅ ドロップイン📋 参考代替品（カタログ未掲載）
INA129PA 最大定格＆電気的特性
| Device Type | Precision, low-power instrumentation amplifier |
| Number of Amplifiers | 1 circuit |
| Maximum Input Offset Voltage | 50 uV |
| Maximum Input Offset Drift | 0.5 uV/degC |
| Maximum Input Bias Current | 5 nA |
| Minimum Common-Mode Rejection Ratio | 120 dB |
| Maximum Protected Input Voltage | -40 V to +40 V |
| Wide Supply Range | Plus or minus 18 V |
| 動作温度範囲 | -40 degC to +85 degC |
| パッケージ | 8-pin plastic DIP |
| 実装タイプ | Through-hole |
| Gain-Setting Resistor | 49.4 kilohm |
INA129PA 8-pin plastic dip ピン配置ガイド
INA129PA (8-pin plastic dip パッケージ) のピン配置。 このアナログコンポーネントは、入力、出力、および電源ピンを備えています。オフセットナル、補償、イネーブルピンの設定については、メーカーのデータシートを参照してください。信号調整やアンプ回路に最適です。
詳細なピン配置データはありません: INA129PA.
詳細は データシート をご参照ください。
主な用途
INA129PA の用途: 6 件s: Bridge Sensor Signal Conditioning, Current Shunt Measurement, Industrial Process Monitoring, Precision Data Acquisition, Low-Level Differential Signal Conditioning, Robust Sensor Interface with Input Protection.
Bridge Sensor Signal Conditioning
The INA129PA fits bridge-sensor front ends where a small differential signal must be amplified while rejecting common-mode excitation and environmental noise. Its verified maximum input offset voltage of 50 uV, maximum offset drift of 0.5 uV/degC, and minimum CMRR of 120 dB support accurate measurements from resistive strain, pressure, and load-cell bridges. Place the amplifier near the bridge outputs and use balanced routing to preserve common-mode rejection. Because the source impedance can be high, the verified 5 nA maximum input bias current is especially important. Confirm the gain equation, input common-mode limits, and bridge excitation requirements from the manufacturer datasheet before setting the gain resistor.
おすすめ
Current Shunt Measurement
The INA129PA is suitable for measuring the small voltage developed across a current shunt while rejecting the supply or conductor voltage common to both shunt terminals. The verified 120 dB minimum CMRR helps suppress that common-mode level, while the 50 uV maximum offset voltage limits signal-independent measurement error. Its 5 nA maximum input bias current is beneficial when the shunt and interconnect produce meaningful source impedance. Route the Kelvin sense traces as a differential pair and keep the amplifier outside high-current switching paths. Verify output swing, shunt excitation, gain, and thermal conditions against the complete manufacturer documentation.
おすすめ
Industrial Process Monitoring
The INA129PA can condition low-level differential process signals where sensor excitation, electrical noise, and temperature drift threaten measurement accuracy. Its verified maximum offset drift of 0.5 uV/degC, maximum input bias current of 5 nA, and minimum CMRR of 120 dB support stable operation with high-impedance transducers and imperfectly balanced sources. Place the device close to the sensor connector, provide a stable reference for the amplifier and downstream conversion, and avoid placing sensitive traces beside motor or relay wiring. The complete gain equation, common-mode range, and output limits must be checked because those values were not included in the supplied verified excerpts.
おすすめ
Precision Data Acquisition
The INA129PA is appropriate for precision data-acquisition inputs requiring low offset, low temperature drift, and strong common-mode rejection. The verified 50 uV maximum input offset and 0.5 uV/degC maximum drift reduce errors in slow, high-resolution measurements, while the 120 dB minimum CMRR helps isolate the intended differential signal from system noise. Use short, balanced input traces, guard or shielding techniques for very high source impedances, and place filtering close to the relevant pins. Verify the available gain and bandwidth because the supplied data does not expose those values, and avoid assuming that a large programmed gain remains stable at the target sampling rate.
おすすめ
Low-Level Differential Signal Conditioning
The INA129PA can amplify low-level differential signals when common-mode voltage and source imbalance would impair a conventional single-ended amplifier. Its verified minimum CMRR of 120 dB, 5 nA maximum input bias current, and 50 uV maximum input offset voltage directly support precision conditioning stages. Place the device close to the source, maintain similar impedance and geometry on the two input paths, and provide stable supply decoupling. Input protection is specified to -40 V and +40 V, but protected inputs are not substitutes for correctly rated surge protection. Confirm operating common-mode limits and output swing before applying the device to bipolar sensor signals.
おすすめ
Robust Sensor Interface with Input Protection
The INA129PA is useful when an instrumentation interface may encounter voltages larger than its normal operating range. The verified input-protection rating of -40 V to +40 V provides an additional robustness margin for exposed sensor wiring, subject to the manufacturer’s current-limit and power-state conditions. Its 120 dB minimum CMRR and low 50 uV maximum offset remain useful after the signal reaches the amplification stage. Add external series resistance, clamps, or surge protection where fault energy could exceed the device rating. The protected range must not be confused with unrestricted input current capability, and system grounding must prevent transients from shifting the inputs beyond absolute limits.
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: INA129PA — 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 | INA129P | INA128PAG4 |
|---|---|---|---|
| Package | 8-PDIP | 8-PDIP | 8-PDIP |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Device Type | Precision, low-power instrumentation amplifier | Instrumentation amplifier | Precision instrumentation amplifier |
主な差別化要因
- Low input offset and drift for precision measurements （vs INA128PAG4)
- High verified common-mode rejection （vs INA129P)
- Defined input protection for exposed sensor connections （vs INA128PAG4)
- Known gain-setting implementation （vs INA129P)
設計ノート
Route the two input conductors as a balanced differential pair from the sensor or shunt to the INA129PA. Keep the amplifier close to the source, avoid sharing sensitive traces with switching-node connections, and use a solid ground reference. Input-impedance mismatch can reduce the available common-mode rejection, which is specified at a minimum of 120 dB under defined conditions. The 50 uV maximum offset and 0.5 uV/degC maximum drift also make connector and via resistance relevant, particularly when the source impedance is high.
Do not treat the -40 V to +40 V input-protection rating as permission for unlimited fault current. Verify the absolute-maximum input conditions, input-current limits, power-state restrictions, and any external clamp requirements in the current Texas Instruments datasheet. The part also uses a specific 49.4 kilohm gain-setting arrangement, while INA128-family devices use different internal values and gain equations. Recalculate the gain when changing amplifier families rather than retaining the original external resistor blindly.
For high-impedance sensors, minimize leakage from PCB contamination, humidity, connectors, and guarding surfaces. The verified 5 nA maximum input bias current is a key starting point, but the complete input-bias-current-versus-temperature curve and leakage of the external sensor and board must also be checked. Add input filtering only after accounting for capacitor leakage and added noise. At high common-mode levels, preserve symmetric routing and a low-impedance ground so the 120 dB minimum CMRR can translate into real system rejection.
コンプライアンス情報
The supplied verified excerpts did not state RoHS, REACH, halogen-free, conflict-minerals, or automotive-qualification status. The -40 degC to +85 degC operating range and 8-pin plastic DIP package are verified, but they do not establish compliance or AEC-Q100 qualification.
