OPI1264B - 10kV Optically Coupled Isolator, NPN Output, Axial
N.º da peça: OPI1264B ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $3.8 | $3,80 |
| 10 | $3.42 | $34,20 |
| 100 | $3.04 | $304,00 |
| 500 | $2.66 | $1.330,00 |
| 1.000 | $2.28 | $2.280,00 |
OPI1264B Visão geral
An optocoupler (also called an optoisolator) is a semiconductor device that conveys an electrical signal between two circuits using a short optical transmission path while maintaining electrical isolation between input and output. The hierarchy is: optocoupler -> isolator -> interface IC -> semiconductor. Optocouplers are essential in the signal chain when a low-voltage control domain (logic, MCU) must interface with a high-voltage or noisy domain (motor drive, power stage, medical patient circuit) without a galvanic connection, providing both safety isolation and noise immunity.
Key features include a typical Current Transfer Ratio (CTR) of 50 percent at If = 10 mA, a collector-emitter breakdown of 30 V or higher, an isolation voltage of 10 kV DC between input and output, and a wide operating temperature window of -55 to +100 C. The 4-pin axial through-hole form factor suits PCB layouts where creepage and clearance distances must be maximised on a single physical axis, which is harder to achieve with flat DIP optocouplers.
The OPI1264B uses a hermetically opaque molded body to block ambient light, ensuring the phototransistor responds only to the internal IR LED. The LED's 890 nm wavelength is matched to the silicon phototransistor's peak responsivity (~850-900 nm) for efficient optical coupling. Compared to flat-package alternatives, the axial lead geometry lengthens the isolation path, which is the primary mechanism behind the 10 kV rating rather than higher internal dielectric strength.
Typical applications include switch-mode power supply (SMPS) feedback loops, medical patient-isolation interfaces, industrial PLC I/O modules, solar inverter gate-drive feedback, and high-voltage analog signal acquisition. The device is commonly placed in the feedback path of an isolated AC-DC converter or as a digital signal isolator between a microcontroller and a 230 V AC / 400 V DC bus.
Design consideration: derate CTR with temperature - at +85 C, CTR drops to roughly 50-60 percent of its +25 C value. Always select the input forward current with adequate margin (typically 1.5x to 2x the minimum needed at room temperature) so that end-of-life CTR and temperature derating do not push the design out of regulation. A base-emitter resistor (typically 1 MΩ to 10 MΩ) across the phototransistor speeds turn-off and prevents leakage-induced false turn-on in DC-coupled applications.
Alternativas drop-in para OPI1264B — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
OPI1264C
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
OPI1266
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
OPI1268
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
OPI1264B Especificações
| Isolation Voltage | 10 kV DC (15 kV DC per DigiKey listing) |
| Number of Channels | 1 |
| Tipo de saída | NPN Silicon Phototransistor |
| Input Type | DC (Infrared LED, 890 nm) |
| Encapsulamento / Caixa | Axial, 4-Lead Through-Hole |
| Número de pinos | 4 |
| Current Transfer Ratio (CTR) | 50 % minimum (typical at If = 10 mA) |
| Tensão coletor-emissor (Vceo) | 30 V |
| Forward Current (If) | 40 mA |
| Temperatura de operação | -55 C to +100 C |
| Tipo de montagem | Through-Hole (Axial Leads) |
| Status RoHS | Compliant |
| Lead-Free | Yes |
Configuração de pinos do OPI1264B
| Pino 1 | LED Anode — Input side - infrared LED anode (forward current input) |
| Pino 2 | LED Cathode — Input side - infrared LED cathode |
| Pino 3 | Collector — Output side - NPN phototransistor collector |
| Pino 4 | Emitter — Output side - NPN phototransistor emitter |
Aplicações típicas
OPI1264B é adequado para 7 aplicaçãos: Switch-Mode Power Supply (SMPS) Feedback Loop, Medical Patient-Isolation Interface, Industrial PLC I/O Module Isolation, Solar Inverter Gate-Drive Feedback, High-Voltage Analog Signal Acquisition, Battery Management System (BMS) High-Voltage Isolation, Industrial Sensor Signal Isolation.
Switch-Mode Power Supply (SMPS) Feedback Loop
The OPI1264B's 10 kV DC isolation voltage enables primary-to-secondary feedback in isolated AC-DC and DC-DC converters without a galvanic connection, a regulatory requirement in medical and industrial power supplies. The 50% minimum CTR at If=10 mA provides adequate collector current to drive a TL431 or similar shunt reference on the secondary side, while the -55 C to +100 C operating range tolerates the thermal stress of a sealed power supply enclosure. Designers place a 1 MΩ to 10 MΩ base-emitter resistor across the phototransistor to accelerate turn-off and prevent leakage-induced false turn-on in continuous-duty regulation. The axial footprint maximizes creepage distance on the PCB, helping meet 8 mm or 10 mm primary-secondary clearance without a cutout. Compared to DIP-6 optocouplers, the axial geometry is harder to source but gives superior isolation per unit board length.
Recomendado
Medical Patient-Isolation Interface
In medical equipment such as patient monitors, infusion pumps, and ECG acquisition modules, the OPI1264B's 10 kV DC isolation provides a safety barrier between patient-connected circuits and mains-powered digital logic. The optical transmission path eliminates ground-loop currents that could otherwise flow through a patient, and the absence of a galvanic link prevents fault propagation from the mains domain to the patient domain. The -55 C to +100 C window supports continuous operation in equipment that is sterilised or operates in clinical environments with elevated ambient temperature. Designers must verify that creepage and clearance distances around the axial leads meet IEC 60601-1 reinforced insulation requirements - the axial package geometry is preferred specifically because it lengthens the surface distance on the PCB. End-of-life CTR derating must be considered: design for at least 2x the minimum collector current at the LED drive current used.
Recomendado
Industrial PLC I/O Module Isolation
Programmable Logic Controller (PLC) digital input modules frequently use axial-package optocouplers such as the OPI1264B to isolate 24 V or 120 V AC field-side signals from the 5 V logic backplane. The 10 kV DC rating exceeds the typical 2.5 kV isolation needed for industrial 24 V systems, providing substantial margin for surge events such as IEC 61000-4-5 transient overvoltages. The NPN phototransistor output interfaces directly with the PLC's 5 V logic via a pull-up resistor, simplifying the input conditioning circuit. The wide -55 C to +100 C operating range supports outdoor cabinets, machine tools, and unheated enclosures. Industrial designers typically select the OPI1264C (higher CTR) over OPI1264B for low-current field inputs where LED drive must be minimised to reduce heat dissipation in dense I/O cards.
Recomendado
Solar Inverter Gate-Drive Feedback
Photovoltaic inverters operating at 600 V to 1500 V DC bus voltages require reinforced isolation between the high-voltage power stage and the low-voltage control MCU. The OPI1264B's 10 kV DC isolation rating easily handles the working voltage plus transient margin required for solar string inverters, and the axial package geometry ensures the primary-to-secondary creepage distance satisfies IEC 62109-1. Used in the gate-drive fault feedback path or in auxiliary supply feedback loops, the OPI1264B transmits trip signals from the IGBT/SiC power stage to the MCU without risking common-mode breakdown. The 50% CTR minimum at 10 mA LED drive is sufficient for fault signaling at speeds below 100 kbps. Compared to digital isolators like ADuM3150, the OPI1264B is lower cost but slower; the trade-off is acceptable for protection and feedback signals that operate at sub-MHz rates.
Recomendado
High-Voltage Analog Signal Acquisition
In high-side current sensing, voltage monitoring, and partial discharge detection circuits, the OPI1264B transmits an analog representation of a high-voltage node to a low-voltage ADC while blocking the common-mode voltage that would otherwise destroy the ADC. The OPI1264B's linear region in the Ic vs If curve is suitable for low-bandwidth analog feedback - typically below 50 kHz - which fits protection relay and battery management use cases. The 50% minimum CTR at 10 mA drive is the key parameter for setting the analog gain; designers bias the LED at a constant current and read the phototransistor collector current through a transimpedance amplifier. The 30 V Vceo rating of the phototransistor sets the maximum local supply rail on the secondary side. For higher bandwidth or better linearity, a linear optocoupler such as IL300 is preferred, but at 10x the cost.
Recomendado
Battery Management System (BMS) High-Voltage Isolation
Lithium-ion battery stacks for electric vehicles and grid storage operate at 400 V to 800 V DC; the OPI1264B isolates the high-voltage battery monitoring signal paths from the low-voltage 12 V domain. The 10 kV DC isolation rating exceeds the typical 2.5 kV working voltage plus transient margin required by IEC 60664-1 for 800 V battery systems. The OPI1264B transmits cell-balancing commands, fault flags, and temperature sensor data across the isolation barrier at rates below 100 kHz, which is sufficient for slow BMS telemetry. The -55 C to +100 C temperature window supports under-hood automotive and outdoor stationary battery installations. Designers should ensure the LED forward current is derated to at most 20 mA continuous to maximise lifetime, since replacing a failed optocoupler in a sealed battery pack is far more expensive than the device itself.
Recomendado
Industrial Sensor Signal Isolation
Industrial 4-20 mA current loops, RTD temperature probes, and strain gauge sensors in high-noise factory environments benefit from the OPI1264B's galvanic isolation between the field-side sensor and the controller-side ADC. The 10 kV isolation blocks ground loops between machines powered from different phases or different buildings, eliminating 50/60 Hz common-mode noise that would otherwise saturate the ADC input. The NPN phototransistor output linearises acceptably when biased in the active region, allowing analog sensor data to be transferred with less than 5% nonlinearity across the operating range. Industrial sensor designers typically choose the OPI1264C over the OPI1264B for higher CTR consistency, which simplifies the analog gain calibration. The axial through-hole package is preferred in industrial environments where the PCB is conformally coated and subjected to vibration - axial leads survive mechanical stress better than flat SMD optocouplers.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para OPI1264B — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | OPI1264C | OPI1266 | OPI1268 |
|---|---|---|---|---|
| Brand | TT Electronics | TT Electronics | TT Electronics | TT Electronics |
| Package | Axial, 4-Lead Through-Hole | Axial, 4-Lead Through-Hole - same | Axial, 4-Lead Through-Hole - same | Axial, 4-Lead Through-Hole - same |
| Operating Temperature | -55 C to +100 C | -55 C to +100 C | -55 C to +100 C (typical family spec) | -55 C to +100 C (typical family spec) |
| Mounting Type | Through-Hole (Axial) | Through-Hole (Axial) | Through-Hole (Axial) | Through-Hole (Axial) |
| RoHS Compliance | Yes | Yes | Yes | Yes |
Principais diferenciais
- 10 kV DC isolation voltage in axial through-hole package (vs 4N25 / PC817 DIP-6 optocouplers)
- Axial lead geometry maximises PCB creepage distance (vs DIP-6 optocouplers)
- Higher CTR minimum grade available in same package (vs OPI1264B vs OPI1264C)
Notas de projeto
The OPI1264B's 10 kV DC isolation rating depends on the surface creepage distance between input-side and output-side PCB traces, not just the internal dielectric of the device. Maintain at least 10 mm of creepage on the PCB between the LED-side and phototransistor-side copper pours. Avoid running any signal traces under the axial body. Place a slot or cutout in the PCB directly under the device if the application requires reinforced insulation per IEC 60747-5-5 - this doubles the effective isolation distance and is a standard practice for medical and solar inverter designs.
CTR degrades by approximately 30-50% over decades of operation and by 40-50% over the -55 C to +100 C operating range. Always design the LED forward current at 1.5x to 2x the minimum value needed at +25 C so the phototransistor collector current stays within the operating region at end-of-life and at maximum temperature. Failing to apply this margin is the most common cause of optocoupler-related field failures in long-lifecycle products (medical, industrial, solar).
The OPI1264B has a typical bandwidth of 50-100 kHz when used as an analog signal isolator; for digital signals, the propagation delay is typically 5-20 microseconds. Add a base-emitter resistor (1 MΩ to 10 MΩ) across the phototransistor to discharge the base-collector junction capacitance and speed up turn-off; without it, low-frequency digital signals may show a slow trailing edge that causes logic errors at the receiver. If higher bandwidth is required, consider a digital isolator (e.g., ADuM3150) or a linear optocoupler (IL300), but at significantly higher cost.
Estimated: at maximum continuous LED forward current of 40 mA and forward voltage of approximately 1.2 V, the LED dissipates approximately 48 mW of heat. The axial package dissipates this into the PCB and ambient air; ensure the device is not placed adjacent to hot components (transformers, power resistors) and that the local ambient temperature near the device does not exceed +70 C in a sealed enclosure. The 40 mA rating is absolute maximum for pulsed operation; derate to 20 mA continuous for maximum LED lifetime.
Informações de conformidade
RoHS and lead-free per TT Electronics documentation and DigiKey distributor listing. Not AEC-Q100 qualified - this is an industrial/medical grade optocoupler, not automotive grade.
