5000Vrms isolation in a 4-lead 6-SOIC
The Toshiba TLP385(D4GR-TL,E is a single-channel transistor-output optocoupler in a compact 6-SOIC package with 4 leads. The DC input side drives a phototransistor rated for 80V output and 50mA per channel, with a current transfer ratio (CTR) guaranteed between 100% and 300% at a forward current of 5mA.
CTR window and drive margin
The CTR is specified as 100% minimum and 300% maximum at 5mA forward current. That window matters for production yield: a tight CTR range means less variation in the collector current across temperature and over the part's lifetime, so the downstream logic sees a consistent drive level. At 5mA input, the output transistor saturates with a maximum Vce of 300mV, which keeps the logic-low voltage well within TTL or CMOS thresholds.
The 6-SOIC body is 4.40mm wide with 4 populated leads, leaving two unused pins for creepage distance.
RoHS compliant per the listing, which simplifies EU and UKCA declarations for finished goods. The forward voltage is 1.25V typical, and the maximum DC forward current is 50mA — stay within that to avoid degrading the LED over time.