Single-channel transistor-output optocoupler for isolated signal transfer
The Vishay VOS617A-7T is a single-channel optocoupler with a phototransistor output, designed for galvanic isolation between a DC input and a transistor load. It provides 3750Vrms isolation in a compact 4-SOIC surface-mount package (4.40mm width, supplier device package 4-SSOP), making it suitable for space-constrained boards in industrial controls, power supplies, and PLC I/O modules. The current transfer ratio spans 80% to 160% at a forward current of 5mA, giving a predictable gain for driving logic inputs or low-current loads up to 50mA per channel and 80V output.
The 3750Vrms isolation rating is the reinforcement dielectric withstand voltage for one minute per IEC 60747-5-5. This covers reinforced insulation requirements for mains-isolated AC-DC supplies and motor-drive interfaces where the buyer needs a single-device barrier without an external isolation transformer. The 80%–160% CTR window at 5mA forward current is a tighter bin than the wide 50–600% spread of generic parts like PC817 — it reduces LED drive current variation across reels, which matters when the output must reliably saturate a downstream logic gate or MOSFET gate driver over temperature.
Temperature range and switching performance
The 3µs typical rise and fall times and 6µs turn-on / 4µs turn-off are adequate for 50/60 Hz zero-crossing detection, relay coil drive, and low-speed digital isolation up to about 50 kbps — not for high-speed comms like I²C or CAN. The 400mV max Vce saturation at the output transistor keeps voltage drop low when driving a 5V or 3.3V logic input.
It is ROHS3 compliant.