THS3112ID - Dual 110 MHz Current-Feedback Amplifier | Texas Instruments
N.º de pieza: THS3112ID ✓ ActivoTHS3112ID Descripción general
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.
Alternativas directas para THS3112ID — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
THS3112CD
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
THS3122ID
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
THS3125ID
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
THS3112ID Valores máximos y características eléctricas
| 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 |
| Encapsulado | 8-SOIC, 0.154 inch (3.90 mm) body width |
| Tipo de montaje | Surface mount |
| Packaging | Tube |
| Minimum Order Quantity | 1 unit |
| Manufacturer Lead Time | 12 weeks |
| Estado del ciclo de vida | Active |
| Estado RoHS | ROHS3 compliant |
| Communication Equipment Support | Supported application |
| Video Distribution Support | Supported application |
| Motor Driver Support | Supported application |
| Piezo Driver Support | Supported application |
Guía de configuración de pines de THS3112ID 8-soic, 0.154 inch (3.90 mm) body width
Configuración de pines para THS3112ID (encapsulado 8-soic, 0.154 inch (3.90 mm) body width). Este componente analógico presenta pines de entrada, salida y alimentación. Consulte la hoja de datos del fabricante para conocer las configuraciones de los pines de ajuste de offset, compensación y habilitación. Ideal para circuitos de acondicionamiento de señal y amplificadores.
No hay datos detallados de patillaje disponibles para THS3112ID.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
THS3112ID es adecuado para 6 aplicacións: 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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para THS3112ID — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | 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 |
Diferenciadores clave
- Higher nominal gain-bandwidth product than the related THS3122 family (frente a THS3122ID)
- Documented low-current-noise performance (frente a THS3122ID)
- Dual high-speed channels in an 8-SOIC package (frente a THS3125ID)
Notas de diseño
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.
Información de cumplimiento
The product listing identifies THS3112ID as ROHS3 compliant. No separate REACH, lead-free, halogen-free, conflict-minerals, or automotive qualification statement was provided.
