INA105KU - Unity-Gain Differential Amplifier | Texas Instruments
部品番号: INA105KU ✓ 生産中INA105KU 概要
A unity-gain differential amplifier is an analog signal-conditioning device that compares two input voltages and produces an output proportional to their difference. The INA105 integrates a precision operational amplifier with a laser-trimmed on-chip metal-film resistor network, placing it in the hierarchy of differential amplifier, instrumentation signal conditioner, analog amplifier IC, and semiconductor.
The principal benefits of the INA105 include a minimum common-mode rejection ratio of 86 dB over temperature, maximum gain error of 0.01%, and maximum nonlinearity of 0.001%. The matched, laser-trimmed resistor network improves gain accuracy and common-mode rejection without external adjustments. The unity-gain configuration also simplifies system design when the desired circuit function is VOUT equal to VIN+ minus VIN-.
The device accepts differential input signals while rejecting common-mode voltage present on both inputs. This makes it useful in current-sense measurement, instrumentation, signal isolation, audio front ends, and industrial signal-conditioning systems. Its SOIC-8 surface-mount package supports compact analog boards while providing separate supply, reference, input, output, and resistor-network connections.
Typical uses include differential sensor interfaces, bridge-amplifier signal paths, balanced audio inputs, and precision measurement systems. For each application, input and output filtering should be selected according to the signal bandwidth and noise requirements. The reference connection should be handled carefully in single-supply systems because it establishes the output reference point.
The key design consideration is common-mode and output-range compatibility. The input common-mode range must include the signal being measured, and the output must remain within the amplifier's output-voltage range at the selected supply voltage. Check the datasheet limits for input common-mode voltage, output swing, supply voltage, and load current before finalizing the board.
This page combines the INA105KU electrical characteristics, package information, pin assignment, application guidance, design checks, and available cross-reference information to support faster component selection and board-layout planning.
ドロップイン代替品: INA105KU — 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。
INA105KU/2K5
✅ ドロップイン📋 参考代替品（カタログ未掲載）
AMP03GS-REEL
✅ ドロップイン📋 参考代替品（カタログ未掲載）
INA105KU 最大定格＆電気的特性
| Product Type | Precision unity-gain differential amplifier |
| Number of Amplifier Channels | 1 |
| Gain | 1 (unity gain) |
| Typical Input Offset Voltage | 500 uV |
| Bandwidth | 1 MHz |
| 動作温度範囲 | -40°C to +85°C |
| Minimum Common-Mode Rejection Ratio | 86 dB over temperature |
| Maximum Gain Error | 0.01% |
| Maximum Nonlinearity | 0.001% |
| パッケージ | 8-pin SOIC |
| 実装タイプ | Surface mount |
| Integrated Resistor Network | Laser-trimmed on-chip metal-film network |
| External Gain Adjustment | Not required |
| Common-Mode Rejection | 86 dB minimum over temperature |
| AEC-Q100 Qualification | not_applicable |
INA105KU ピン構成
| ピン 1 | RG — Gain-setting resistor-network terminal |
| ピン 2 | IN- — Inverting differential input |
| ピン 3 | IN+ — Non-inverting differential input |
| ピン 4 | V- — Negative supply connection |
| ピン 5 | REF — Reference input |
| ピン 6 | OUT — Single-ended output |
| ピン 7 | V+ — Positive supply connection |
| ピン 8 | NC — Not connected (per datasheet) |
主な用途
INA105KU の用途: 6 件s: Current-Sense Amplification, Precision Bridge Signal Conditioning, Balanced Audio Input, Industrial Instrumentation Interface, Data-Acquisition Front End, Balanced Sensor and Communications Interface.
Current-Sense Amplification
The INA105KU is suitable for current-sense measurements where the output must represent the voltage difference across a shunt resistor. Its unity-gain differential input arrangement avoids an external precision resistor network, while the 86 dB minimum common-mode rejection helps preserve accuracy when the shunt voltage is small relative to the supply level. Place the amplifier close to the shunt and route the differential traces as a matched pair. Confirm that the shunt common-mode voltage remains inside the INA105 input common-mode range and that the output swing remains valid at the maximum expected current.
おすすめ
Precision Bridge Signal Conditioning
The INA105KU can condition low-level differential outputs from resistive bridge sensors without external gain-setting resistors. The integrated laser-trimmed resistor network provides a unity-gain differential-to-single-ended conversion, while the 0.01% maximum gain error and 86 dB minimum common-mode rejection support accurate bridge measurements. Use the reference terminal to establish the output offset in single-supply systems, and verify that the bridge excitation voltage and sensor output remain inside the amplifier's common-mode and output limits.
おすすめ
Balanced Audio Input
The INA105KU can serve as the differential input stage for a balanced audio signal when the required bandwidth is within its 1 MHz specification. Its unity-gain topology converts the difference between the two conductors into a single-ended signal and rejects common-mode content present on both lines. The 500 uV typical input offset is important for low-level audio conditioning, although system-level noise and gain should also be evaluated. Add input filtering appropriate to the audio bandwidth and maintain a clean return path to reduce ground-potential errors.
おすすめ
Industrial Instrumentation Interface
The INA105KU is appropriate for industrial instrumentation interfaces that require accurate differential measurement in an 8-pin surface-mount package. The device's -40°C to +85°C operating range supports industrial equipment, and its internal precision resistor network reduces the need for manually matched external components. The differential inputs should be routed away from switching nodes, with symmetric layout and solid grounding used to preserve common-mode rejection. Confirm the supply voltage, input range, and output swing against the nominal and transient conditions of the controlled process signal.
おすすめ
Data-Acquisition Front End
The INA105KU can provide analog conditioning ahead of a data-acquisition converter when the source is differential and unity gain is preferred. Its 1 MHz bandwidth covers many general-purpose measurement paths, while its laser-trimmed internal network simplifies calibration by avoiding external resistor-ratio errors. The anti-aliasing filter should be designed at the converter's actual bandwidth, and the amplifier output must meet the ADC input range. Provide local supply decoupling and route the differential input pair together to minimize conversion of switching noise into an apparent measurement error.
おすすめ
Balanced Sensor and Communications Interface
The INA105KU can be used in balanced sensor or communications interfaces where unwanted common-mode voltage appears on both signal conductors. Its minimum 86 dB common-mode rejection over temperature and unity-gain operation make it a straightforward way to recover the differential component. Keep the input traces short and symmetrical, and avoid placing the amplifier near high-current switching paths. The application should also account for the 500 uV typical offset, which can influence the resolution of very small sensor signals, and for the output swing limits at the selected supply voltage.
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: INA105KU — 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 | INA105KU/2K5 | AMP03GS-REEL |
|---|---|---|---|
| Package | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC - pin-compatible candidate |
| Brand | Texas Instruments | Texas Instruments | Analog Devices |
| Function | Precision unity-gain differential amplifier | Precision unity-gain differential amplifier | Unity-gain differential amplifier replacement candidate |
| Gain | 1 | 1 | 1 |
主な差別化要因
- Integrated precision resistor network （vs AMP03GS-REEL)
- Confirmed common-mode rejection （vs AMP03GS-REEL)
- Specified precision offset and bandwidth （vs AMP03GS-REEL)
設計ノート
Verify the input common-mode range and output swing against the actual supply voltage before finalizing the circuit. A unity-gain differential amplifier can still clip when the common-mode voltage is too high or when the reference level places the output outside its valid range. In single-supply designs, calculate the required REF voltage and ensure that both the input midpoint and output remain within the datasheet limits at minimum and maximum load.
Route IN+ and IN- as a closely spaced differential pair, keep them away from switching nodes and high-current return paths, and connect the REF bypass capacitor close to its pin when required by the application. Use a continuous ground reference beneath or immediately adjacent to the analog section. These practices reduce differential-to-common-mode conversion, helping preserve the INA105's specified 86 dB minimum common-mode rejection over temperature.
Place the normal input, output, and reference bypass capacitors close to their corresponding pins, following the values and layout shown in the manufacturer datasheet. Keep supply-return current out of the sensitive input and reference paths. Because the INA105 is a precision analog amplifier, stable reference and supply decoupling can be more valuable than an aggressive, high-frequency capacitor network that introduces unwanted board resonances.
Treat the output as driving the selected load and the next-stage input capacitance. Do not add an isolation resistor arbitrarily: it can interact with output capacitance and alter frequency response. If an output filter is required, calculate its cutoff using the actual load and capacitance, then verify stability and bandwidth using the amplifier data and the complete output network.
コンプライアンス情報
The INA105KU is a general-purpose precision analog amplifier rather than an automotive-qualified device. RoHS, REACH, lead-free, halogen-free, and conflict-minerals status require confirmation from the manufacturer or current product documentation.