LT1012CH - Picoamp Precision Op Amp | Analog Devices
部品番号: LT1012CH ✓ 生産中LT1012CH 概要
An operational amplifier is an analog integrated circuit that amplifies the voltage difference between its inverting and non-inverting inputs. The LT1012 belongs to the precision operational-amplifier hierarchy, combining high open-loop gain with low offset, low bias current, and low-noise behavior. These characteristics make it useful when the source impedance can be high enough that input bias-current error would overwhelm a conventional amplifier.
The LT1012's principal features include picoampere bias currents maintained across the full -55°C to +125°C temperature range, microvolt offset voltage, low offset drift with time and temperature, and exceptionally high common-mode and power-supply rejection ratios. According to the manufacturer, precision operation on two Ni-Cad batteries is possible with 1 mW of power dissipation. The reported 5 mA load-current capability and gain of one million are particularly useful for precision buffer, instrumentation, transducer, and low-level signal-chain applications.
The LT1012 is implemented as a bipolar precision amplifier and is internally compensated for unity-gain stability. This architecture supports simple voltage-follower use without external compensation while retaining accurate low-frequency operation. The high gain and very low input current also make the device suitable for guarding, electrochemical measurement, photodiode amplification, and other applications where source leakage and offset can dominate measurement accuracy.
Typical uses include precision sensor interfaces, low-current transducers, battery-powered instruments, pH and conductivity measurement circuits, photodiode amplifiers, and analog test equipment. The hermetic metal-can package provides a mechanically robust option for applications requiring stable operation over an extended temperature range, although engineers should observe the manufacturer's specified lead orientation and connection requirements.
When using the LT1012CH, minimize leakage around the input pins and keep sensitive input traces away from power and ground paths. Because very high open-loop gain makes offset, bias-current error, and leakage especially important, clean PCB surfaces, guarded inputs, suitable bypassing, and careful source-impedance balancing are essential. This page combines verified manufacturer and distributor information with practical implementation guidance and clearly identified drop-in alternatives.
ドロップイン代替品: LT1012CH — 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。
LT1012AH
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
LT1012ACH
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
LT1012CH 最大定格＆電気的特性
| Product Type | Internally compensated precision operational amplifier |
| Number of Circuits | 1 circuit |
| Input Bias Current | 30 pA |
| Input Offset Voltage | 10 µV |
| Voltage Gain | 1,000,000 at unity-gain operation |
| Load Current | 5 mA |
| Power Dissipation on Two Ni-Cad Batteries | 1 mW |
| 動作温度範囲 | -55°C to +125°C |
| Temperature Grade | Commercial |
| パッケージ | 8-lead round TO-5 metal can with wire leads |
| Terminal Count | 8 terminals |
| 実装タイプ | Through-hole |
| Compensation | Internally compensated |
LT1012CH 8-lead round to-5 metal can with wire leads ピン配置ガイド
LT1012CH (8-lead round to-5 metal can with wire leads 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: LT1012CH.
詳細は データシート をご参照ください。
主な用途
LT1012CH の用途: 6 件s: High-Impedance Sensor Instrumentation, Electrochemical and pH Probe Interfaces, Battery-Powered Precision Meters, Photodiode and Optical Sensor Amplification, Precision Current-to-Voltage Conversion, Analog Test and Measurement Equipment.
High-Impedance Sensor Instrumentation
The LT1012CH fits high-impedance sensor front ends because its 30 pA input bias current minimizes the bias-current error that would otherwise appear across a high source impedance. A typical circuit buffers the sensor output with the amplifier configured as a voltage follower, preserving the signal while providing much lower output impedance for the next measurement stage. The reported 10 µV offset voltage and voltage gain of one million support accurate low-level amplification, while the -55°C to +125°C range covers demanding industrial environments. Practical implementation requires guarded input traces, clean surfaces, and careful isolation from grounded leakage paths.
おすすめ
Electrochemical and pH Probe Interfaces
The LT1012CH is appropriate for electrochemical probes because their source impedance can be extremely high and leakage-sensitive. Its picoampere-class 30 pA input bias current minimizes unwanted current through the probe and adjacent insulation, while the 10 µV offset voltage limits input-referred error in low-level measurements. Designers commonly use a follower or inverting configuration followed by a higher-precision conversion stage. The TO-5 metal-can package offers a robust through-hole construction for laboratory and industrial instruments, but guarding, clean connectors, and moisture control remain essential because contamination can dominate the amplifier's otherwise very low input error.
おすすめ
Battery-Powered Precision Meters
The LT1012CH supports compact battery-powered meters because Analog Devices states that the LT1012 operates precisely on two Ni-Cad batteries with 1 mW power dissipation. The amplifier can still deliver a 5 mA load current and provides a voltage gain of one million, allowing the device to serve directly as a high-gain sensor amplifier rather than merely a buffer. Low bias current is especially valuable when conserving battery energy and measuring weak currents. The system designer should still account for sensor current, display load, regulator efficiency, and temperature, since the stated 1 mW figure describes the LT1012 operating condition rather than complete instrument consumption.
おすすめ
Photodiode and Optical Sensor Amplification
The LT1012CH can amplify photodiode and optical-sensor outputs where the available signal current is small and leakage errors must be minimized. Its 30 pA input bias current is low enough for many precision photodiode circuits, while the high open-loop gain and microvolt offset support accurate transimpedance or follower configurations. The 5 mA output-current capability permits useful drive into the next stage. Designers should add diode guarding, keep the input node compact, avoid contamination, and account for photodiode capacitance; those external factors often determine bandwidth and settling behavior more strongly than the nominal amplifier noise figures.
おすすめ
Precision Current-to-Voltage Conversion
The LT1012CH is suitable for precision current-to-voltage conversion because its picoampere input bias current produces less error with high-value feedback and sensing impeditors, and its reported voltage gain of one million supports accurate amplification of small generated voltages. The 10 µV input offset specification contributes only a small input-referred error when the useful signal is sufficiently larger than that value. Designers should use guarded, low-leakage feedback resistors and clean PCB surfaces to avoid contamination currents that can exceed the specified bias current. Stable layout and temperature management are particularly important in long-duration measurements where drift and board leakage can materially affect repeatability.
おすすめ
Analog Test and Measurement Equipment
The LT1012CH can serve as a precision input stage in analog test equipment, where leakage, offset, and common-mode errors affect the accuracy of the instrument under test. Its 30 pA bias current, 10 µV offset voltage, very high common-mode rejection, and very high power-supply rejection make it useful in buffer, gain, and measurement-amplifier arrangements. The manufacturer specifically highlights practically unmeasurable warm-up drift and operation over -55°C to +125°C, supporting stable calibration in demanding equipment. Layout should isolate sensitive inputs from power converters and relay contacts, while adequate input bypassing helps preserve the high power-supply rejection described by the manufacturer.
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: LT1012CH — 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 | LT1012AH | LT1012ACH |
|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices |
| Package | 8-lead round TO-5 metal can | 8-lead round TO-5 metal can - same package family | 8-lead round TO-5 metal can - same package family |
| Product Type | Internally compensated precision operational amplifier | LT1012-family precision operational amplifier | LT1012-family precision operational amplifier |
| Number of Circuits | 1 circuit | 1 circuit | 1 circuit |
| Input Bias Current | 30 pA | Picoampere-class LT1012-family bias current | Picoampere-class LT1012-family bias current |
| Input Offset Voltage | 10 µV | Microvolt-class LT1012-family offset | Microvolt-class LT1012-family offset |
| Operating Temperature Range | -55°C to +125°C | -55°C to +125°C for the LT1012 family | -55°C to +125°C for the LT1012 family |
| Load Current | 5 mA | 5 mA for the LT1012 family | 5 mA for the LT1012 family |
| Voltage Gain | 1,000,000 | 1,000,000 for the LT1012 family | 1,000,000 for the LT1012 family |
| Power Dissipation on Two Ni-Cad Batteries | 1 mW | 1 mW for the LT1012 family | 1 mW for the LT1012 family |
| Compensation | Internally compensated | Internally compensated LT1012-family architecture | Internally compensated LT1012-family architecture |
主な差別化要因
- Picoampere input bias current for high-source-impedance measurement （vs LT1012AH)
- Microvolt input offset supports low-level signal accuracy （vs LT1012ACH)
- High gain with useful load-current capability （vs LT1012AH)
設計ノート
Protect the high-impedance input node with guarding and keep it physically short. Route the input away from switching nodes, relay contacts, power-supply traces, and grounded test points. If the application uses the LT1012CH as a follower, connect the inverting input directly to the output near the device to minimize parasitic feedback capacitance. Inspect the assembled board for flux residue, condensation, and contamination because leakage across a high-impedance node can exceed the specified 30 pA input bias current.
Do not infer substitute compatibility from the round metal-can package alone. The LT1012CH uses an 8-terminal TO-5 configuration, and a replacement must match the exact lead numbering and function assignments, not merely the physical outline. Before using LT1012AH or LT1012ACH, compare the current manufacturer ordering table, electrical limits, screening grade, offset limits, and drift limits. The supplied search results do not expose a complete CH-versus-AH comparison table, so final approval should follow a documented manufacturer review.
Place the power-supply bypass capacitor close to the LT1012CH supply pins and return it directly to the appropriate ground reference. This helps preserve the high power-supply rejection emphasized by Analog Devices, especially when the amplifier follows a switching converter. Confirm the complete operating supply range, input/output common-mode limits, output-current demand, and thermal conditions from the official datasheet before finalizing the power network; these values are not quantified in the supplied distributor snippets.
Avoid adding large input or feedback capacitance without checking stability and settling behavior. The LT1012 is internally compensated, but the practical bandwidth of a noise-gain stage depends on total capacitance at the inverting input and the source impedance. Use the manufacturer's recommended feedback values and compensation guidance for the selected gain. At high closed-loop gains, verify resistor tolerance and temperature coefficient because their noise and drift can exceed the amplifier's own input-referred error.
コンプライアンス情報
The supplied verified web data does not state RoHS, REACH, lead-free, halogen-free, or conflict-minerals status. AEC-Q100 is not applicable because the LT1012CH is presented as a commercial-grade instrumentation amplifier rather than an automotive-qualified device.
