5000Vrms isolation in a 4-pin SOIC
The Toshiba TLP385(D4BL-TL,E is a single-channel transistor-output photocoupler in a 6-SOIC package with 4 leads, providing 5000Vrms galvanic isolation between a DC input LED and a phototransistor output. The output transistor is rated for 80V maximum and 50mA continuous current, with a Vce saturation of 300mV typical — enough to drive logic-level inputs or small relays directly. The current transfer ratio spans 200% to 600% at a forward current of 5mA, giving design margin for degraded LED output over temperature and life.
CTR range and switching speed
With a minimum CTR of 200% at 5mA, this part can maintain a logic-high output even with significant LED current droop due to temperature or aging. The typical turn-on and turn-off times are both 3µs, with rise and fall times of 2µs and 3µs respectively, making it suitable for 100 kbps signalling or slower — not a high-speed digital isolator, but adequate for status feedback, relay drivers, and isolated I/O in industrial controllers.
Temperature range and environment
Rated for -55°C to 110°C operating temperature, this photocoupler can be deployed in environments from cold storage to engine-bay adjacent electronics. The wide temperature grade suits industrial automation, motor drives, and power-supply feedback loops where ambient heat is a concern.
Lifecycle and compliance
Listed as Active product status, with RoHS compliance. The Tape & Reel variant (D4BL suffix) is the standard reel option; cut tape is also available for prototyping.