Isolation and transfer ratio for BOM fit
The TCLT1105 is a single-channel optocoupler from Vishay with a transistor-plus-base output, rated for 5000 Vrms isolation between input and output. That isolation rating suits it for galvanic barrier applications in industrial controls, motor drives, and power supplies where the safety standard demands reinforced insulation. Its current transfer ratio spans 50% to 150% at a forward current of 5 mA — a wide enough band that the CTR bin covers both low-drive and high-sensitivity loads without needing a tighter-sorted part. The DC input type means it switches on a steady forward current, not an AC waveform.
Output ratings and switching speed
The output transistor can handle up to 80 V collector-emitter and 50 mA continuous current — enough to drive a small relay coil, a PLC input, or a logic gate directly. Saturation voltage is capped at 300 mV, keeping the on-state power loss low in the output leg. Typical rise and fall times are 3 µs and 4.7 µs respectively; turn-on time is 6 µs, turn-off 5 µs. This gives a practical switching ceiling around 20 kHz for clean pulse transmission — adequate for isolating PWM signals or serial data at moderate baud rates.
Package and temperature range
Operating temperature spans -55°C to 100°C, covering industrial enclosures, outdoor telecom cabinets, and automotive under-hood zones that stay below the 100°C ceiling. The forward voltage is 1.25 V typical at rated current, and the maximum continuous forward current is 60 mA.