What this Darlington optocoupler does for your board
The TLP387(D4-TPR,E is a single-channel DC-input Darlington-output optocoupler from Toshiba, housed in a 6-SOIC surface-mount package with 4 leads. It provides 5000 Vrms of galvanic isolation between the LED side and the photodarlington output, making it a solid choice for industrial controls, PLC I/O modules, and motor-drive interface circuits where noise immunity and safety isolation are required. The minimum current transfer ratio is 1000% at 1 mA forward current.
Output voltage and current — what you can actually drive
The output stage is rated for a maximum collector-emitter voltage of 300 V and can sink up to 150 mA continuously per channel. Switching speed is modest — turn-on time is 50 µs typical, turn-off is 15 µs, with rise and fall times of 40 µs and 15 µs respectively. This part is not for high-frequency PWM or data transmission; it is for on/off control at line-rate or slower, like enabling a power supply or latching a contactor.
Is it still in production? Sourcing and lifecycle
For volume BOM lines, we source and quote to order against your quantity — no stock-holding claim, but we can confirm availability and pricing at quote time.
The 6-SOIC package has a 0.173-inch body width and 4.40 mm height, with only 4 leads populated — the centre two pins are omitted for creepage distance. The 4-lead layout is standard for high-voltage optocouplers, and the footprint matches common 6-SOIC patterns. Surface-mount assembly is straightforward with standard reflow profiles.