What this optocoupler does in the isolation barrier
The Vishay VO615A-8X001 is a single-channel phototransistor optocoupler in a 4-DIP through-hole package. It provides 5000Vrms galvanic isolation between a DC input LED and a phototransistor output, with a current transfer ratio (CTR) guaranteed between 130% and 260% at a forward current of 5mA. This makes it a straightforward choice for isolating logic-level signals in industrial controls, power supplies, and motor drives where the input and output grounds must be separated.
5000Vrms isolation — what it buys you
The 5000Vrms isolation rating is the headline safety spec. It means the part can withstand 5 kV RMS between input and output for one minute per the standard test. That covers reinforced insulation requirements for many industrial and medical applications where the barrier must survive transient overvoltages and fault conditions. For a 4-DIP package, this is a strong isolation figure — you typically see 3750Vrms or 5000Vrms in this footprint, and the 5000Vrms variant gives more margin in high-noise environments or where regulatory creepage distances are tight.
The CTR of 130% to 260% at 5mA forward current is the key parametric for design margin. A minimum of 130% means the phototransistor will deliver at least 6.5 mA collector current when the LED is driven at 5 mA (assuming the output is biased correctly). That gives you enough headroom to drive a logic gate input or a small relay coil without needing a separate gain stage. The 260% maximum bounds the worst-case saturation risk — if you design the pull-up resistor for the minimum CTR, the maximum won't swamp the output. The 5mA test condition is a common bias point, so the part drops into existing designs without recalculating the LED drive resistor.
Temperature range and environment
The -55°C low end is unusual for a standard optocoupler — many stop at -40°C — so this part suits cold-start conditions in northern-climate equipment or avionics bay environments. The 110°C upper limit is typical for industrial-grade; it keeps the CTR stable through the rated range without derating the output current.
Output ratings and switching speed
The phototransistor output is rated for 70V maximum collector-emitter voltage and 50mA continuous current per channel. That covers 24V and 48V logic rails with margin, plus small solenoid or indicator loads.
Package and mounting
Through-hole mounting is preferred for hand-assembly, rework, or high-vibration environments where a socket adds reliability.
Lifecycle and compliance
No end-of-life notice or last-time-buy is recorded. The ROHS3 compliance covers the latest restricted-substance exemptions, so it is acceptable for new designs shipping into EU markets.