3750Vrms isolation — the safety margin that matters
The VOM618A-X001T is a single-channel optocoupler from Vishay with a transistor output, designed for galvanic isolation in DC-input circuits. Its 3750Vrms isolation voltage provides the creepage and clearance needed for reinforced insulation in industrial power supplies, motor drives, and PLC digital inputs. The 4-SOP gull-wing package suits automated surface-mount assembly, and the -55°C to 110°C operating range covers both outdoor telecom cabinets and factory-floor enclosures without derating.
CTR spread: 50% to 600% at 1 mA — design for the worst case
The current transfer ratio spans 50% minimum to 600% maximum at a forward current of 1 mA. That is a 12:1 spread across units. For a logic-level interface, size the input resistor so the minimum CTR still saturates the output transistor (Vce sat max 400 mV) at the required load current. The 50 mA per-channel output current ceiling and 80 V output breakdown give headroom for driving relays, LEDs, or low-side switches in 24 V industrial buses.
Switching speed: 5 µs rise, 4 µs fall — not for high-speed data
Typical rise and fall times are 5 µs and 4 µs respectively, with turn-on/turn-off times of 7 µs and 6 µs. This optocoupler is intended for DC-level sensing, status feedback, and low-frequency signal isolation — not for high-speed serial links or PWM gate drive above a few kilohertz. The DC input type means the LED is driven with a steady forward current; AC-coupled signals need an external rectifier or a dedicated AC-input optocoupler.