Isolation rating and transistor output — what the 5 kV and CTR mean for your design
The FOD2741ASD: That 5 kV isolation is the withstand voltage for one minute per the datasheet — it provides galvanic isolation between a low-voltage DC control side and a higher-voltage or noisy circuit side, such as in switch-mode power supply feedback loops, PLC digital inputs, or motor drive signal isolation. The current transfer ratio (CTR) is specified at 100% minimum and 200% maximum, both at 10 mA forward current. This means that with 10 mA into the LED, the output phototransistor can sink between 10 mA and 20 mA at the collector — the range accounts for process variation and temperature drift. The 100% floor ensures sufficient drive margin for the downstream logic or relay coil even at temperature extremes.
Package and temperature grade — surface-mount assembly in industrial environments
Housed in an 8-SMD gull wing package (supplier device package 8-SMD), the FOD2741ASD is designed for surface-mount reflow assembly. The gull wing leads provide visual solder joint inspection and some compliance for thermal expansion mismatch between the PCB and the package body. The output transistor is rated for 30 V maximum collector-emitter voltage and 50 mA maximum continuous collector current.
Active lifecycle and compliance — no imminent end-of-life, ROHS3 certified
The base product number is FOD2741; the suffix ASD indicates the specific package and tape-and-reel configuration.