The Toshiba TLP385(GB,E is a single-channel phototransistor optocoupler that delivers 5000Vrms galvanic isolation in a compact 4-lead SO-6 package (6-SOIC body, 4.40mm width, 4 leads populated). It is the 'GB' CTR bin, guaranteeing a current transfer ratio between 100% and 600% at 5mA forward current — a wide enough window to accommodate LED aging and temperature drift without redesigning the input resistor. The output transistor is rated to 80V and 50mA continuous, so it can drive a 24V PLC input, a relay coil with an external transistor, or a 48V industrial bus interface with comfortable margin.
Temperature range and switching speed — bench realities
Rated from -55°C to 110°C, this part covers cold-start automotive, outdoor telecom cabinets, and engine-bay-adjacent enclosures. The 2µs rise and 3µs fall times (typical) place it in the medium-speed class — fine for 10 kHz PWM or 115.2 kbps serial isolation, but not for high-speed fieldbus or switch-mode feedback loops. Turn-on and turn-off times are both 3µs typical, so the propagation delay is symmetric within a microsecond, which simplifies timing budget in a synchronous interface.
Listed as Active with RoHS compliance confirmed.