Product Overview
The TLP521-2GBF is a dual-channel transistor-output photocoupler from Toshiba Electronic Devices & Storage Corporation. Each channel consists of a gallium arsenide (GaAs) infrared LED optically coupled to an NPN silicon phototransistor, providing 2500 Vrms of electrical isolation between the input and output sides in an 8-pin DIP package. The GB CTR (Current Transfer Ratio) rank guarantees a transfer ratio of 100% to 600% at I_F = 5 mA and V_CE = 5 V, making it suitable for both digital switching and analog signal transfer applications. Each channel supports up to 50 mA collector current and 55 V collector-emitter voltage, with a collector-emitter saturation voltage of 0.4 V maximum. UL 1577 recognized and RoHS compliant, the TLP521-2GBF is a widely used general-purpose optocoupler for signal isolation in programmable controllers, AC/DC input modules, switching power supply feedback circuits, telecommunications equipment, and industrial automation systems where galvanic isolation between different voltage domains is required.
Key Specifications
| Type | Dual-Channel Phototransistor Output Photocoupler |
| Number of Channels | 2 |
| Input | GaAs infrared LED |
| Output | NPN silicon phototransistor |
| CTR Rank (GB) | 100% to 600% @ I_F=5mA, V_CE=5V |
| Collector-Emitter Voltage (V_CEO) | 55 V (min) |
| Emitter-Collector Voltage (V_ECO) | 7 V (min) |
| Collector Current (I_C) | 50 mA (max per channel) |
| Forward Current (I_F) | 50 mA (max) |
| Pulse Forward Current | 1 A (100 us pulse, 100 pps) |
| Collector-Emitter Sat. Voltage | 0.4 V (max @ I_C=2.4mA, I_F=8mA) |
| Isolation Voltage (BVS) | 2500 Vrms (min, 1 min) |
| Isolation Resistance | 10^11 ohms (typ.) |
| Isolation Capacitance | 0.8 pF (typ.) |
| Switching Time (turn-on) | ~2 us (typ.) |
| Switching Time (turn-off) | ~25 us (typ.) |
| LED Forward Voltage | 1.15 V (typ @ I_F=10mA) |
| Collector Power Dissipation | 100 mW (per channel) |
| Operating Temperature | -55 degC to +100 degC |
| Safety Standards | UL 1577 recognized |
| RoHS Compliant | Yes |
| Package | DIP-8 (through-hole) |
Features
- Dual-channel phototransistor output photocoupler
- CTR rank GB: 100% to 600% current transfer ratio
- 2500 Vrms isolation voltage (1 minute)
- 55 V collector-emitter breakdown voltage
- 50 mA collector current per channel
- Low saturation voltage: 0.4 V max
- Two independent, electrically isolated channels
- GaAs infrared LED with long life
- UL 1577 safety recognized
- RoHS compliant
Applications
- Programmable logic controllers (PLC) – AC/DC input modules
- Switching power supply feedback and isolation
- Digital signal isolation and level shifting
- Industrial control and factory automation
- Telecommunications equipment isolation
- Motor drive and control circuits
- Computer peripheral interfaces
- Consumer appliances and white goods
- UPS and battery management systems
- Sensor signal conditioning and isolation