5000Vrms isolation in a 4-lead SO-6
The Toshiba TLP385(GRL,E is a single-channel transistor-output optocoupler in a 6-SOIC package with only 4 leads populated — the two unused pins are omitted, saving board space while maintaining 5000Vrms of galvanic isolation between input and output. The input is a DC-driven IR LED with a typical forward voltage of 1.25V; the output is a phototransistor rated for 80V collector-emitter and 50mA continuous current.
CTR window: 100% to 200% at 5mA
The current transfer ratio is specified as a minimum of 100% and a maximum of 200%, both measured at 5mA forward current. That 2:1 spread is tighter than many general-purpose optocouplers, which means less variation in the collector current from unit to unit. For a digital input where you are sinking a logic gate, the 100% floor guarantees at least 5mA on the output side at 5mA input — enough to drive a standard CMOS or TTL load without extra gain stages. The 200% ceiling prevents the output from saturating too hard, keeping turn-off time predictable.
Switching speed: 2µs rise, 3µs fall
Rise and fall times are 2µs and 3µs typical, with turn-on and turn-off both at 3µs.
Temperature range and environment
Operating temperature range is -55°C to 110°C.