THS3112ID - Dual 110 MHz Current-Feedback Amplifier | Texas Instruments
部品番号: THS3112ID ✓ 生産中THS3112ID 概要
A current-feedback amplifier is a voltage-feedback amplifier variant whose closed-loop bandwidth depends primarily on the feedback resistor rather than the closed-loop gain. This architecture is useful in high-speed signal paths because it can preserve bandwidth as gain increases, provided the feedback network, source impedance, and output loading are designed correctly. In the signal-chain hierarchy, the THS3112ID belongs to the operational-amplifier family, specifically high-speed current-feedback instrumentation amplifiers used for analog signal conditioning.
The THS3112ID offers a 110 MHz gain-bandwidth product and low current noise, making it appropriate for wideband transimpedance, video, communications, and buffered-signal applications. Its current-feedback architecture supports high output drive, which is valuable when driving downstream analog stages, cable terminations, or capacitive loads. The dual configuration also allows two independent high-speed amplifier channels in one package, reducing board area in stereo, differential, or multi-channel signal-conditioning systems.
In a transimpedance application, the inverting input serves as the summing node and a feedback resistor converts photocurrent or sensor current into voltage. The 10.8 pA/√Hz inverting current noise directly affects sensitivity in this topology. The 2.9 pA/√Hz noninverting current noise is especially relevant when the amplifier is configured with a non-inverting gain path. Capacitance at the summing node should be minimized because it interacts with the feedback network and can create peaking or instability.
The device is commonly considered for communication equipment, video distribution, motor drivers, and piezo drivers. In video paths, the wide bandwidth allows larger closed-loop bandwidth than a conventional general-purpose amplifier. In motor and piezo systems, the high output-current capability can improve drive into reactive loads, although stability and safe operating limits must be checked for the actual load and output waveform.
For PCB implementation, use a short feedback loop and place feedback resistors close to the inverting input. Keep the non-inverting input and ground-return paths compact to minimize parasitic capacitance and feedback from adjacent high-speed signals. Avoid capacitive loading directly at the output; use an isolation resistor when driving long cables or highly capacitive loads.
This product page combines the manufacturer’s device information with package, lifecycle, and sourcing details, plus application guidance, design notes, and verified drop-in replacement analysis. Use the manufacturer datasheet pin-description table and ordering information as the authoritative references for final schematic, footprint, and qualification decisions.
ドロップイン代替品: THS3112ID — 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。
THS3112CD
✅ ドロップイン📋 参考代替品（カタログ未掲載）
THS3122ID
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
THS3125ID
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
THS3112ID 最大定格＆電気的特性
| Amplifier Type | Dual current-feedback amplifier |
| Number of Circuits | 2 circuits |
| Gain-Bandwidth Product | 110 MHz |
| Noninverting Current Noise | 2.9 pA/√Hz |
| Inverting Current Noise | 10.8 pA/√Hz |
| Output Drive | High output current |
| Feedback Architecture | Current feedback |
| パッケージ | 8-SOIC, 0.154 inch (3.90 mm) body width |
| 実装タイプ | Surface mount |
| Packaging | Tube |
| Minimum Order Quantity | 1 unit |
| Manufacturer Lead Time | 12 weeks |
| ライフサイクル状態 | Active |
| RoHS ステータス | ROHS3 compliant |
| Communication Equipment Support | Supported application |
| Video Distribution Support | Supported application |
| Motor Driver Support | Supported application |
| Piezo Driver Support | Supported application |
THS3112ID 8-soic, 0.154 inch (3.90 mm) body width ピン配置ガイド
THS3112ID (8-soic, 0.154 inch (3.90 mm) body width 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: THS3112ID.
詳細は データシート をご参照ください。
主な用途
THS3112ID の用途: 6 件s: Photodiode and Sensor Signal Conditioning, Video Distribution and Buffering, Communications Equipment Signal Paths, Motor Driver Analog Control, Piezo Driver and High-Impedance Drive, Precision Audio and Instrumentation Front End.
Photodiode and Sensor Signal Conditioning
The THS3112ID fits low-level current-to-voltage conversion because its inverting current noise is 10.8 pA/√Hz and its noninverting current noise is 2.9 pA/√Hz. In a transimpedance topology, the device converts sensor or photodiode current into a voltage that can be sampled by an ADC. Its 110 MHz gain-bandwidth product provides bandwidth for fast sensor events, while the high output-drive capability supports the next analog stage. Keep the feedback resistor and summing node compact because excessive node capacitance can alter stability and introduce peaking.
おすすめ
Video Distribution and Buffering
The THS3112ID is suitable for wideband video buffering because it combines a 110 MHz gain-bandwidth product with two amplifier channels and high output-current capability. Each channel can buffer a source into a downstream distribution stage while preserving signal integrity across short PCB routes or controlled-length cables. The 8-SOIC package supports compact dual-channel layouts. Maintain a short feedback loop, provide a low-impedance reference return, and use an output isolation resistor when the load contains substantial capacitance or long-cable inductance.
おすすめ
Communications Equipment Signal Paths
The THS3112ID can condition communications signals where bandwidth, low current noise, and output drive are important. Its 110 MHz gain-bandwidth product supports wideband amplification, while 2.9 pA/√Hz noninverting current noise is favorable for high-impedance signal sources. Use the dual amplifier for matched transmit or receive channels and minimize input capacitance to preserve the intended response. Validate the full channel with realistic source impedance, termination, and filtering rather than treating gain bandwidth as a guaranteed signal rate.
おすすめ
Motor Driver Analog Control
The THS3112ID is applicable to the analog control section of a motor-drive system because its high output-current capability provides stronger drive than a general-purpose low-current amplifier. The device can amplify control, position, or current-sense signals before they enter the power stage. Its 110 MHz bandwidth and low-noise architecture are useful for fast feedback loops. Keep sensitive feedback routing compact, ensure the feedback network remains stable with the motor-driver input capacitance, and verify thermal performance across the required duty cycle.
おすすめ
Piezo Driver and High-Impedance Drive
The THS3112ID is suitable for command and drive stages associated with piezo positioning because the high output-current capability can support reactive loads better than a low-drive amplifier. Its 110 MHz gain-bandwidth product allows the amplifier to respond to rapid control waveforms, and the low current-noise figures help preserve weak sensor information. Piezo outputs can present steep capacitive edges, so use an isolation resistor and validate output current, stability, and thermal rise with the actual load rather than evaluating only nominal small-signal behavior.
おすすめ
Precision Audio and Instrumentation Front End
The THS3112ID can serve as a high-bandwidth instrumentation front end when low current noise and drive capability matter. Its dual channels can process two related signals while the 110 MHz gain-bandwidth product supports wideband small-signal work. The noninverting current noise of 2.9 pA/√Hz is especially useful around high-impedance transducers, while the 8-SOIC package simplifies dual-channel routing. Use short input paths, stable reference grounding, and manufacturer-recommended feedback values to preserve the intended noise and stability performance.
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: THS3112ID — 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 | THS3112CD | THS3122ID | THS3125ID |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Amplifier Configuration | Dual current-feedback amplifier | Dual current-feedback amplifier | Dual current-feedback amplifier | Dual current-feedback amplifier |
| Gain-Bandwidth Product | 110 MHz | 110 MHz | Approximately 100 MHz | Approximately 100 MHz |
主な差別化要因
- Higher nominal gain-bandwidth product than the related THS3122 family （vs THS3122ID)
- Documented low-current-noise performance （vs THS3122ID)
- Dual high-speed channels in an 8-SOIC package （vs THS3125ID)
設計ノート
Place the feedback resistor directly beside the inverting input and return its ground-side or summing-node connection through the shortest practical path. Current-feedback amplifiers are sensitive to parasitic capacitance at the summing node because that capacitance combines with the feedback impedance and can alter bandwidth or create peaking. Keep the non-inverting input route short, use a continuous ground plane, and avoid routing high-speed or switching-current traces beneath the feedback network.
Do not treat the 110 MHz gain-bandwidth value as a guaranteed closed-loop bandwidth for every circuit. In a current-feedback amplifier, the feedback resistor value, gain setting, source impedance, and load directly influence the response. Begin with manufacturer-recommended feedback values, add capacitance only when the stability analysis requires it, and verify both frequency response and pulse settling on the completed PCB.
When driving a long cable, coax connection, or input with substantial capacitance, place a small isolation resistor at the amplifier output. This reduces capacitive feedback and ringing while allowing the THS3112ID to retain useful bandwidth. Confirm the resistor value using the load capacitance and target response, and check output-current demand because high output drive is one of the device’s principal advantages.
For sustained high-amplitude output into reactive or low-impedance loads, calculate average dissipation from the actual output waveform, output-current limit, and supply voltage. The THS3112ID’s 8-SOIC package is surface mount but does not remove the need for thermal verification. Provide copper area around the device, control source impedance to avoid excessive current, and confirm that the load and duty cycle keep junction temperature within the manufacturer’s limits.
コンプライアンス情報
The product listing identifies THS3112ID as ROHS3 compliant. No separate REACH, lead-free, halogen-free, conflict-minerals, or automotive qualification statement was provided.
