Selection mistake this part avoids
The VO617A-1 is a single-channel optocoupler from Vishay with a phototransistor output and DC input, packaged in a 4-DIP through-hole body. Its 5300 Vrms isolation rating covers reinforced insulation requirements in medical, industrial, and power-supply applications where a standard 3750 Vrms part would need a second device or external creepage. The 40% to 80% current transfer ratio at 5 mA forward current gives enough gain to drive logic inputs or microcontroller GPIOs directly without a post-amplifier, and the 80 V collector-emitter breakdown handles 24 V and 48 V bus rails cleanly.
What the CTR range means for your drive budget
The 40% minimum CTR at 5 mA is the number to design against when calculating the pull-up resistor and the input threshold margin over temperature. A 5 mA LED drive yields at least 2 mA collector current, which saturates a 4.7 kΩ pull-up to 5 V logic cleanly. The 80% maximum CTR prevents the output from saturating too deeply, keeping turn-off time predictable at 2.3 µs typical. If the LED current drops below 5 mA due to a weak drive or series resistance, the CTR falls off — stay above 3 mA to stay inside the guaranteed range.
Lifecycle and production status
ROHS3 compliant per the supplier declaration. For BOM risk assessment, this part is still a safe selection for new designs and volume production.
Temperature range and deployment environment
Rated for -55°C to 110°C operating ambient, the VO617A-1 suits outdoor telecom cabinets, industrial motor drives, and power converters that see wide thermal cycling. The 110°C upper limit exceeds the typical 85°C industrial grade, giving margin in confined enclosures or near heat sinks. The through-hole 4-DIP package with 7.62 mm pin pitch keeps creepage distance consistent with the 5300 Vrms rating — no conformal-coat derating needed for basic insulation.