PS2801A-1-A - 2500Vrms SSOP-4 Phototransistor Optocoupler | Renesas
N.º de pieza: PS2801A-1-A ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $1.51 | $1,51 |
| 10 | $1.36 | $13,60 |
| 100 | $1.08 | $108,00 |
| 500 | $0.86 | $430,00 |
| 1.000 | $0.72 | $720,00 |
PS2801A-1-A Descripción general
What is an optocoupler? An optocoupler (also called optoisolator or photocoupler) is a semiconductor device that transfers electrical signals between two isolated circuits using light. It contains an infrared LED on the input side optically coupled to a photosensitive detector (phototransistor, phototriac, or photodarlington) on the output side. Optocouplers sit within the broader hierarchy: optocoupler -> isolator -> signal conditioning -> analog/mixed-signal IC -> semiconductor. They are essential for breaking ground loops, providing safety isolation in industrial interfaces, and protecting low-voltage digital logic from high-voltage transients on field-side wiring.
Key features of the PS2801A-1-A include the SSOP-4 footprint which is approximately 35% smaller than a standard SOP-4, enabling high-density PCB layouts in space-constrained designs. The integrated shield effectively blocks ambient light from interfering with the phototransistor's base region, reducing susceptibility to false triggering under bright illumination. The device supports an operating temperature range of -55 °C to +100 °C, and uses Pb-free / RoHS-compliant materials per Renesas manufacturing standards.
From an architectural standpoint, the PS2801A-1-A uses an NPN epitaxial silicon phototransistor rather than a photodarlington, which limits CTR to a maximum of 400% (versus >1000% for darlington optos) but provides markedly faster switching speeds (~3 us rise vs ~50 us for darlington) and superior linearity for analog signal isolation. The GaAs LED is optimized for 940 nm peak emission, matched to the phototransistor's spectral response for maximum quantum efficiency.
Typical applications include digital logic isolation in PLCs and industrial control systems, isolated gate-drive interfaces, communication line isolation in RS-232/RS-485 transceivers, and feedback path isolation in switching power supplies. The 70 V VCEO rating is sufficient to interface directly with 24 V industrial logic levels. The wide CTR range (50-400%) requires design margin; bias resistors must be selected to guarantee saturation and switching at end-of-life CTR (typically 50%).
When designing with this device, calculate the input-side current using IF = (VF + VF_LED_margin) / RLED, ensuring IF remains in the 5-20 mA linear region for stable CTR. On the output side, choose a collector resistor (RL) that keeps the phototransistor out of saturation for analog applications, or fully saturated for digital switching. Add a base-emitter resistor (typically 1-10 MΩ) to improve noise immunity and switching speed. Always observe the 2500 Vrms isolation voltage in creepage/clearance calculations for end-product safety certifications (UL 1577, IEC 60747-5-5).
This page synthesizes distributor pricing, drop-in replacement alternatives from Renesas and competing optocoupler families, and practical PCB layout guidance not found in the standalone datasheet PDF.
Alternativas directas para PS2801A-1-A — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
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PS2801A-1-A-L
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PS2801A-1-A-N
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PS2801-1-A
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PS2801A-1-F3-K-A
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PS2801A-1-A Valores máximos y características eléctricas
| Manufacturer | Renesas Electronics (also offered by CEL) |
| Part Number | PS2801A-1-A |
| Product Type | Phototransistor Output Optocoupler (DC Input, Single Channel) |
| Encapsulado | 4-SSOP (Shrink Small Outline Package, 4-pin) |
| Number of Channels | 1 |
| Isolation Voltage | 2500 Vrms |
| Maximum Collector-Emitter Voltage (VCEO) | 70 V |
| Maximum Collector Current | 30 mA |
| Maximum Forward Current (IF) | 30 mA |
| Typical Forward Voltage (VF) | 1.2 V at IF = 10 mA |
| Typical VCE(sat) | 130 mV at IF = 10 mA, IC = 2 mA |
| Current Transfer Ratio (CTR) | 50% to 400% (IF = 5 mA, VCE = 5 V) |
| Rise Time (tr) | 3 µs (typical) |
| Fall Time (tf) | 5 µs (typical) |
| Temperatura de funcionamiento | -55 °C to +100 °C |
| Input Type | DC |
| Tipo de salida | Transistor (NPN silicon phototransistor) |
| Estado RoHS | Compliant (Pb-free) |
Configuración de pines de PS2801A-1-A
| Pin 1 | Anode — LED anode (positive input); connect via current-limiting resistor to logic supply |
| Pin 2 | Cathode — LED cathode (input ground); connect to input-side ground |
| Pin 3 | Emitter — Phototransistor emitter; connect to output-side ground via pull-down or directly |
| Pin 4 | Collector — Phototransistor collector; connect to output supply via pull-up resistor (RL) |
Aplicaciones típicas
PS2801A-1-A es adecuado para 7 aplicacións: PLC Digital Input Isolation, Switch-Mode Power Supply Feedback Isolation, RS-485/RS-232 Communication Line Isolation, Isolated Gate Driver for IGBT/MOSFET, Medical Equipment Patient Isolation, Audio Equipment Ground-Loop Elimination, Industrial Sensor Signal Isolation.
PLC Digital Input Isolation
The PS2801A-1-A is widely used in PLC (Programmable Logic Controller) digital input modules to isolate 24V field-side signals from the 5V/3.3V backplane logic. Its 2500 Vrms isolation safely separates the industrial field wiring from the controller's sensitive microcontroller, while the 50%-400% CTR range allows direct interfacing with 24V DC inputs through a single current-limiting resistor. The 70 V VCEO rating comfortably exceeds 24V industrial rail levels, and the SSOP-4 footprint keeps each input channel compact. The integrated ambient light shield prevents false triggering under factory lighting. Engineers typically bias the LED at 5-10 mA via a 2.2 kΩ resistor and use a 47 kΩ collector pull-up to 5V for noise-immune digital switching up to 10 kHz.
Recomendado
Switch-Mode Power Supply Feedback Isolation
In isolated AC-DC and DC-DC converters, the PS2801A-1-A provides the galvanic isolation barrier in the primary-to-secondary feedback path. The optocoupler's 2500 Vrms isolation meets the requirements of IEC 60950 / IEC 62368-1 for reinforced insulation in IT equipment. Its 3 µs/5 µs rise/fall times support switching frequencies up to approximately 100 kHz, sufficient for most quasi-resonant and fixed-frequency SMPS topologies. The 70 V VCEO and 30 mA collector current are well-matched to TL431 reference shunt circuits commonly used in primary-side regulation. The PS2801A-1-A's CTR range (50-400%) must be accounted for in the TL431 bias network to maintain loop gain across the device's operating life and temperature range.
Recomendado
RS-485/RS-232 Communication Line Isolation
The PS2801A-1-A provides ground-loop isolation for serial communication interfaces in industrial networks. By placing the optocoupler in the data or handshake line path between the transceiver IC and the bus connector, designers break ground potential differences that would otherwise cause data errors or damage to interface ICs. The device's 30 mA maximum collector current is compatible with typical RS-232/RS-485 driver outputs. For half-duplex RS-485, two PS2801A-1-A devices (one per direction) can isolate the differential pair. Note that high-speed RS-485 (>1 Mbps) requires a digital isolator instead; the PS2801A-1-A is best suited to 115.2 kbps and lower industrial protocols such as Modbus RTU, Profibus, and DeviceNet at 12 Mbps.
Recomendado
Isolated Gate Driver for IGBT/MOSFET
For low-to-medium power IGBT and MOSFET gate drive circuits, the PS2801A-1-A can be used as a simple isolated driver for non-critical switching applications. Its 2500 Vrms isolation is adequate for 400V-600V DC bus systems typically found in motor drives and solar inverters. However, designers should note the phototransistor output is current-limited (~30 mA), making this optocoupler suitable only for low gate-charge MOSFETs (Qgs < 10 nC) or as a pre-driver stage. For high-current gate drive or high-side applications, a dedicated gate-drive optocoupler (e.g., Renesas PS9551, Toshiba TLP350) with integrated gate-driver output is recommended. The 3 µs rise time limits switching frequency to about 50 kHz in this application.
Recomendado
Medical Equipment Patient Isolation
The PS2801A-1-A's 2500 Vrms isolation is suitable for patient-connected medical devices requiring IEC 60601-1 reinforced insulation between the patient side and the operator-accessible circuitry. Typical applications include isolated signal paths in patient monitors, infusion pumps, and ECG machines where the device protects the patient from hazardous leakage currents. The Pb-free / RoHS-compliant materials meet medical device environmental requirements. Note that for cardiac-floating (CF) applications requiring 5000 V isolation, a higher-isolation optocoupler is required. The SSOP-4 footprint enables compact patient-wearable designs where PCB real estate is at a premium.
Recomendado
Audio Equipment Ground-Loop Elimination
In professional audio equipment, the PS2801A-1-A can be used to break ground loops between interconnected devices such as mixers, amplifiers, and signal processors. By isolating the audio signal path with the optocoupler, designers eliminate the 50/60 Hz hum caused by ground potential differences between AC-powered equipment. The NPN phototransistor's superior linearity compared to a photodarlington makes the PS2801A-1-A particularly suitable for analog audio signal isolation (though bandwidth is limited to about 100 kHz). For digital audio (S/PDIF, AES3) or high-fidelity line-level signals, an audio-specific digital isolator or transformer is preferred. The integrated ambient light shield prevents hum modulation from fluorescent lighting in studio environments.
Recomendado
Industrial Sensor Signal Isolation
The PS2801A-1-A is commonly used to isolate 4-20 mA current loop signals and digital sensor outputs in industrial measurement systems. For 4-20 mA loops, the optocoupler provides the isolation barrier between the field-mounted sensor and the controller, allowing accurate current measurement by breaking ground loops. For digital sensors (proximity switches, photoelectric sensors, limit switches), the PS2801A-1-A interfaces directly to the 24V DC sensor output while providing a clean logic-level signal to the microcontroller. The 2500 Vrms isolation protects the controller from voltage transients on long sensor cables. The SSOP-4 footprint is small enough to be placed on the same PCB as the controller, or in a remote termination panel with multiple PS2801A-1-A devices in close proximity.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para PS2801A-1-A — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | PS2801A-1-A-L | PS2801A-1-A-N | PS2801-1-A | PS2801A-1-F3-K-A | PS2801-4-A |
|---|---|---|---|---|---|---|
| Package | 4-SSOP | 4-SSOP - same | 4-SSOP - same | 4-SSOP - same | 4-SSOP - same | 16-SSOP (4-channel) - different |
| Brand | Renesas Electronics | Renesas Electronics - same | Renesas Electronics - same | Renesas Electronics - same | Renesas Electronics - same | Renesas Electronics - same |
| Number of Channels | 1 | 1 | 1 | 1 | 1 | 4 |
| Isolation Voltage | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms |
| VCEO Maximum | 70 V | 70 V | 70 V | 70 V | 70 V | 70 V |
| CTR Range | 50% to 400% | 50% to 400% | 50% to 400% | 50% to 400% | 50% to 400% | 50% to 400% |
| Rise Time (typical) | 3 µs | 3 µs | 3 µs | 3 µs | 3 µs | 3 µs |
| Ambient Light Shield | Yes (integrated) | Yes | Yes | No (legacy design) | Yes | Yes |
| RoHS Compliance | Compliant (Pb-free) | Compliant | Compliant | Compliant | Compliant | Compliant |
| Operating Temperature | -55°C to +100°C | -55°C to +100°C | -55°C to +100°C | -55°C to +100°C | -55°C to +100°C | -55°C to +100°C |
Diferenciadores clave
- Integrated ambient light shield (frente a PS2801-1-A)
- Compact SSOP-4 footprint with high CTR range (frente a PS2801-4-A)
- Multiple packaging/order code options from same die (frente a PS2801A-1-A-L / PS2801A-1-A-N)
Notas de diseño
Never operate the LED below the recommended IF (typically 5 mA minimum for specified CTR). At low currents the CTR falls off sharply and the device may fail to switch reliably at end-of-life. Conversely, do not exceed the absolute maximum IF of 30 mA or the LED degradation accelerates. For 5V logic inputs, a 330 Ω to 470 Ω series resistor typically yields IF ≈ 8-10 mA, providing good margin. For 24V industrial inputs, use 2.2 kΩ to 4.7 kΩ to drop IF to ~5-10 mA after accounting for the LED's 1.2 V VF. Always include a bypass capacitor (100 nF) across the LED to suppress high-frequency noise.
Maintain minimum creepage and clearance distances on the PCB between the input-side (LED anode/cathode, pins 1-2) and the output-side (collector/emitter, pins 3-4) per IEC 60747-5-5. For 2500 Vrms isolation, a minimum 4 mm creepage distance through air is typically required on the PCB surface. Avoid running any copper traces, vias, or component leads between the input and output regions of the optocoupler, as this can compromise the isolation barrier. Place the device over a PCB cutout if the application requires the absolute minimum creepage to be validated. The exposed pad of the SSOP-4 should be soldered to a floating copper island not connected to either input or output ground.
The PS2801A-1-A's phototransistor output is susceptible to dv/dt-induced false triggering in high-noise industrial environments. Add a base-emitter resistor (typically 1-10 MΩ) across pins 3 and 4 to shunt base-collector leakage current and prevent false triggering from fast transient events. For switching speeds above 50 kbps, minimize the collector pull-up resistor value (10 kΩ or lower) to speed up the RC time constant, but verify this stays within the phototransistor's collector current rating (30 mA max). For best noise immunity, use a Schmitt trigger buffer (e.g., 74HC14) at the optocoupler output to clean up slow edges and add hysteresis.
Estimated: At maximum operating temperature (100 °C) and maximum simultaneous LED (60 mW) and transistor (120 mW) power dissipation, the SSOP-4 package's thermal resistance (~250 °C/W on a standard JEDEC test board) results in a junction temperature rise of approximately 45 °C above ambient. This is within the device's rating, but designers should derate IF and IC at temperatures above 85 °C to maintain long-term reliability. The integrated ambient light shield is also a thermal path; in enclosed high-temperature environments, ensure adequate airflow or PCB copper to dissipate the combined ~150 mW worst-case power.
Información de cumplimiento
RoHS compliant per Renesas product page and DigiKey listing. Pb-free / lead-free materials. Halogen-free status not explicitly stated in verified web data. Not AEC-Q100 qualified - this is an optocoupler for industrial/commercial use, not automotive-grade. UL 1577 and IEC 60747-5-5 isolation certifications apply to the device itself.
