The Vishay TCLT1102 is a single-channel phototransistor optocoupler with the base brought out to a separate pin, giving you the option to bias the transistor for faster switching or lower leakage. It comes in a 6-SOP (5-lead) surface-mount package and is rated for 5000Vrms isolation between input and output, which covers reinforced insulation requirements in many industrial and medical power supplies. The DC input side uses an IR LED with a typical forward voltage of 1.25V, and the output transistor can handle up to 80V and 50mA continuous.
The 5000Vrms isolation voltage is the headline spec — it qualifies the TCLT1102 for applications where you need galvanic separation between high-voltage and low-voltage domains, like IGBT gate drivers, motor drive feedback, or isolated sensor interfaces. The 63% to 125% current transfer ratio (CTR) at 10mA forward current gives you a wide margin for logic-level translation: at minimum CTR, 10mA in gives at least 6.3mA out, enough to pull a 5V logic input low through a 1kΩ pull-up. The 80V collector-emitter breakdown means you can interface directly with 24V or 48V industrial buses without a level shifter. Switching speed is modest — typical rise/fall times of 3µs and 4.7µs, with turn-on/turn-off at 6µs and 5µs respectively. That limits the TCLT1102 to data rates below about 100 kbps, fine for status feedback, relay drives, and slow serial links, but not for high-speed communication like CAN or SPI. The base-pin access lets you add a resistor to ground to speed up turn-off at the cost of some CTR, a trick worth knowing if you need to squeeze a few microseconds out of the propagation delay. The 100°C upper limit is the absolute maximum for the case temperature, so derate output current if the part sits near a hot heatsink or power device.
Package and mounting in the field
The 6-SOP (5-lead) package is a surface-mount SOIC-like body, 7.50mm wide, with a 0.295" (7.50mm) lead pitch. The 5-lead count matches the standard 6-pin SOIC footprint with one pin omitted — the base is pin 5, collector pin 4, emitter pin 6. Orientation is marked with a pin 1 dot on the top of the package. In a rework or field repair scenario, the leads are visible and accessible for hand soldering with a fine-tip iron, no hot-air station required. The package is ROHS3 compliant and lead-free per.