LTV-354T-C - AC Input Phototransistor Optocoupler | Lite-On | 4-SOP
N.º da peça: LTV-354T-C ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $0.18 | $0,18 |
| 10 | $0.16 | $1,60 |
| 100 | $0.13 | $13,00 |
| 500 | $0.11 | $55,00 |
| 1.000 | $0.09 | $90,00 |
| 3.000 | $0.07 | $210,00 |
LTV-354T-C Visão geral
An optocoupler (also called an opto-isolator or photocoupler) is a semiconductor device that transmits electrical signals between two isolated circuits using light. The LTV-354T-C belongs to the transistor-output optoisolator subfamily, where an infrared LED on the primary side drives a phototransistor on the secondary side. Within the broader component taxonomy, this places the LTV-354T-C as: optocoupler -> optoisolator -> transistor-output optoisolator -> isolator -> discrete semiconductor interface component. Optocouplers are essential for breaking ground loops, protecting low-voltage logic from high-voltage transients, and providing safety isolation in industrial and consumer equipment that connects to AC mains.
Key features of the LTV-354T-C include a minimum 50 mA forward current capability, 4 us typical rise time and 3 us typical fall time, and JEDEC22A111-compliant wave soldering at 260 +0/-5 C for 10 seconds. The 4-SOP (mini-flat) package footprint is one of the smallest standard optocoupler outlines available, enabling dense PCB layouts in space-constrained designs such as programmable logic controllers, switching power supply feedback loops, and digital logic isolators.
Internally the LTV-354T-C uses two infrared LEDs connected in inverse parallel to form the AC input. This bidirectional input topology supports either AC or DC drive polarity, allowing the same part to be used in both half-wave and full-wave rectifier feedback paths. The phototransistor output provides linear transfer characteristics suitable for both analog signal isolation and digital logic-level shifting.
Typical applications include isolated gate-drive interfaces for power MOSFETs and IGBTs, SMPS primary-to-secondary feedback, AC-line detection circuits, PLC input modules, and ground-loop elimination in industrial sensor interfaces. The 4-SOP footprint and 3750 Vrms isolation voltage also make it suitable for medical equipment meeting basic IEC 60601 isolation requirements.
When designing with the LTV-354T-C, place a current-limiting resistor in series with the LED input based on forward voltage (typically 1.2 V at 20 mA) and observe the maximum forward current rating. A pull-up resistor on the transistor collector sets the logic high level; the CTR (current transfer ratio) determines the collector current for a given LED forward current.
This page synthesizes verified Lite-On datasheet specifications, drop-in 4-SOP optocoupler alternatives, and practical design notes that go beyond the manufacturer's product brief.
Alternativas drop-in para LTV-354T-C — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com LTV-354T-C (mesmo formato e footprint) — diferindo em Operating Temperature, Output Type, Package.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
LTV-354T
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTV-354T-A
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTV-354T-D
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
EL354T
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
TLP181
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
HCPL-2212-500E
✅ Drop-In✓ Em estoque
$2.2 / unidade
Ver ficha técnica →LTV-354T-C Classificações máximas e características elétricas
| Isolation Voltage | 3750 Vrms |
| Number of Channels | 1 |
| Input Type | AC, DC |
| Tipo de saída | Transistor (Phototransistor) |
| Encapsulamento | 4-SOP (Mini-Flat) |
| Tipo de montagem | Surface Mount |
| Rise Time (Typ) | 4 us |
| Fall Time (Typ) | 3 us |
| Forward Current (Max) | 50 mA |
| Reverse Voltage (Max) | 6 V |
| Temperatura de operação | -30 C to +100 C |
| Wave Soldering Peak | 260 +0/-5 C for 10 s (JEDEC22A111) |
| Nível MSL | 1 |
| Status RoHS | Compliant |
| Package Dimensions | 2.0 mm pitch |
Configuração de pinos do LTV-354T-C
| Pino 1 | Anode (LED1) — AC-input LED anode / DC-input forward terminal |
| Pino 2 | Cathode (LED2) — AC-input LED cathode / DC-input return terminal |
| Pino 3 | Emitter — Phototransistor emitter (output side) |
| Pino 4 | Collector — Phototransistor collector (output side, connect to pull-up) |
Aplicações típicas
LTV-354T-C é adequado para 6 aplicaçãos: Isolated SMPS Primary-to-Secondary Feedback, PLC Digital Input Module Isolation, Isolated IGBT / MOSFET Gate Driver Interface, AC-Line Zero-Cross Detection, Medical Equipment Signal Isolation, Ground-Loop Elimination in Industrial Sensors.
Isolated SMPS Primary-to-Secondary Feedback
The LTV-354T-C's AC-input stage and 3750 Vrms isolation make it well suited for switching-mode power supply feedback paths where the primary-side error amplifier and the secondary-side PWM controller must remain galvanically isolated. The bidirectional LED drive tolerates either polarity of the feedback winding output, simplifying the rectifier design on the secondary. With 4 us rise / 3 us fall times the phototransistor can follow the compensation-loop bandwidth of most consumer and industrial SMPS designs up to about 50 kHz. Place the part near the secondary-side reference and use a 10 to 20 mA LED drive to balance CTR linearity and LED lifetime.
Recomendado
PLC Digital Input Module Isolation
In PLC digital input cards, the LTV-354T-C isolates 24 V field-side logic from the backplane 5 V logic domain while withstanding industrial surge and fast-transient events. The AC-input stage supports AC and DC field wiring without polarity concerns, allowing the same module hardware to accept either AC or DC proximity switches. The 3750 Vrms isolation voltage satisfies IEC 61131-2 basic insulation for industrial control equipment, and the 4-SOP mini-flat footprint keeps channel density high on the input card. A 1.5 to 2.2 kohm input resistor limits LED current to roughly 15 mA at 24 V field supply.
Recomendado
Isolated IGBT / MOSFET Gate Driver Interface
The LTV-354T-C provides logic-level isolation between a low-side microcontroller PWM output and the gate-drive circuit of a high-side power switch. Its AC-input stage accepts bidirectional drive signals, useful for half-bridge topologies where the gate reference shifts relative to logic ground. The 4 us rise / 3 us fall times are adequate for switching frequencies up to 25 to 50 kHz in motor-drive and power-conversion circuits. Use a totem-pole driver on the phototransistor output to translate the isolated logic level to the gate-drive supply rail of the power switch.
Recomendado
AC-Line Zero-Cross Detection
The AC-input stage of the LTV-354T-C natively accepts the 50/60 Hz mains waveform, allowing direct connection to a current-limited mains tap through a high-voltage dropping resistor. The phototransistor output produces a logic-level zero-cross signal that an MCU can use to synchronize triac firing, dimmer control, or solid-state relay switching. The 3750 Vrms isolation provides the reinforced insulation barrier required for line-connected equipment, and the 4-SOP package fits inside the small control PCB of a wall-switch or dimmer module. Select the dropping resistor to limit LED peak current to 20 mA at 230 Vrms.
Recomendado
Medical Equipment Signal Isolation
The LTV-354T-C's 3750 Vrms isolation supports patient-applied isolation requirements in IEC 60601-1 medical electrical equipment when used in conjunction with appropriate PCB creepage and clearance. The 4-SOP mini-flat footprint enables compact patient-monitoring front ends such as ECG, SpO2, and blood-pressure modules where multiple isolated channels must fit in a small enclosure. AC-input capability is convenient for transformer-isolated front-end stages where the LED drive is AC-coupled. Verify the isolation voltage against the Means of Patient Protection (MOPP) rating required by the specific medical device classification.
Recomendado
Ground-Loop Elimination in Industrial Sensors
Industrial 4-20 mA loops, RS-485 fieldbus nodes, and thermocouple signal conditioners frequently suffer from ground-potential differences between the sensor site and the controller cabinet. The LTV-354T-C breaks the ground loop by providing 3750 Vrms of galvanic isolation while passing the sensor signal across the barrier with linear CTR characteristics. Its 4 us / 3 us switching speed is fast enough for 4-20 mA loop bandwidth and for low-speed RS-485 signaling up to 19.2 kbps. Place the optocoupler between the field-side amplifier and the controller-side ADC or UART to suppress common-mode transients on long sensor cables.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para LTV-354T-C — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | LTV-354T | LTV-354T-A | LTV-354T-D | EL354T | TLP181 |
|---|---|---|---|---|---|---|
| Package | 4-SOP (Mini-Flat), 2.0 mm pitch | 4-SOP (Mini-Flat) - same | 4-SOP (Mini-Flat) - same | 4-SOP (Mini-Flat) - same | 4-SOP (Mini-Flat) - same | 4-SOP (Mini-Flat) - same |
| Brand | Lite-On | Lite-On | Lite-On | Lite-On | Everlight Electronics | Toshiba |
| Input Type | AC, DC (bidirectional LED) | AC, DC | AC, DC | AC, DC | AC, DC | DC only |
| Isolation Voltage | 3750 Vrms | 3750 Vrms | 3750 Vrms | 3750 Vrms | 3750 Vrms | 3750 Vrms |
| Number of Channels | 1 | 1 | 1 | 1 | 1 | 1 |
| Forward Current (Max) | 50 mA | 50 mA | 50 mA | 50 mA | 50 mA | 50 mA |
| Operating Temperature | -30 C to +100 C | -30 C to +100 C | -30 C to +100 C | -30 C to +100 C | -30 C to +100 C | -55 C to +125 C (wider) |
| RoHS / MSL | RoHS / MSL 1 | RoHS / MSL 1 | RoHS / MSL 1 | RoHS / MSL 1 | RoHS / MSL 1 | RoHS / MSL 1 |
Principais diferenciais
- AC-input stage in 4-SOP mini-flat footprint (vs TLP181 (Toshiba))
- Compact 4-SOP mini-flat footprint with 3750 Vrms isolation (vs LTV-817 series)
- Wide operating temperature range (vs EL354T (Everlight))
Notas de projeto
The LTV-354T-C AC-input LED stage must be current-limited by an external resistor. With a typical forward voltage of 1.2 V at I_F = 20 mA, design the input resistor for 10 to 20 mA peak forward current. For a 24 V DC input a 1.5 to 2.2 kohm resistor is appropriate; for 5 V logic drive a 220 to 330 ohm resistor limits current to roughly 15 to 20 mA. Always observe the 50 mA absolute maximum forward current and add a reverse-blocking diode if DC-reverse polarity protection is required.
Do not assume that all 4-SOP optocouplers share the same pinout. The LTV-354T-C uses pin 1 = anode, pin 2 = cathode, pin 3 = emitter, pin 4 = collector. Some 4-SOP optocouplers such as the Sharp PC3xx series use pin 1 = anode, pin 2 = cathode, pin 3 = collector, pin 4 = emitter (reversed E/C). Verify the pinout against the datasheet before substituting, or footprint misalignment will short-circuit the phototransistor.
Maintain at least 5 mm of PCB creepage distance between the LED side (pins 1-2) and the phototransistor side (pins 3-4) to preserve the 3750 Vrms isolation rating. Do not route any copper traces, vias, or solder mask openings under the optocoupler body, and avoid placing ground planes beneath the part. The 4-SOP mini-flat package has a 2.0 mm pitch, so two pads per side leave generous space for creepage traces on the outside of the land pattern.
The phototransistor output of the LTV-354T-C is a current-mode device; convert it to logic-level with a pull-up resistor (typically 4.7 kohm to 10 kohm) on the collector. For high-speed logic-level shifting, add a Schmitt-trigger buffer such as a 74LVC1G14 between the collector and the receiving logic to clean up the slow phototransistor edges (4 us rise / 3 us fall). Avoid driving long cables directly from the open-collector output to prevent EMI pickup and false triggering from coupled noise.
Informações de conformidade
RoHS compliant per Lite-On product declaration. MSL 1 rated per JEDEC J-STD-020. Wave soldering peak 260 C / 10 s per JEDEC22A111. Not AEC-Q100 qualified - automotive applications should select an AEC-Q100-grade optocoupler.
