High-voltage Darlington optocoupler for industrial isolation
The Toshiba TLP387(TPR,E is a single-channel DC-input Darlington-output optocoupler rated for 5000Vrms isolation, making it a fit for galvanic isolation barriers in motor drives, industrial PLCs, and medical power supplies where the primary and secondary sides must be electrically separated. The Darlington output gives a minimum current transfer ratio of 1000% at 1 mA forward current, so the LED drive current can be kept low — useful when the primary-side controller has limited drive capability or you want to minimise power draw across the isolation boundary. Output can switch up to 300V and sink 150 mA continuously, enough to drive a small relay, a DC solenoid, or a logic-level input directly without a buffer transistor.
Switching speed and timing budget
Turn-on time is 50 µs typical, turn-off 15 µs typical, with rise and fall times of 40 µs and 15 µs respectively.
Package, footprint, and storage notes
Housed in a 6-SOIC package with 4 leads (0.173" body width, 4.40 mm body height) — the standard small-outline footprint for medium-power optocouplers. The 4-lead pinout is the same as many Toshiba and competitor Darlington optocouplers in this package class, so a layout done for a TLP388 or similar will accept the TLP387 with no board change. The part is surface-mount only.
Temperature range and environment
The 110°C ceiling is below the 125°C typical of automotive-grade parts, so for under-hood or high-temperature industrial applications verify the junction temperature stays within the limit at full load. The 5000Vrms isolation rating is a reinforced isolation level per IEC 60747-5-5, suitable for medical (MOPP) and industrial (basic/reinforced) isolation barriers.
Lifecycle and compliance
The ROHS3 status means it is fully compliant with the latest EU RoHS directive, including all phthalate restrictions.