Isolation barrier and input flexibility
The FOD814A3SD is a single-channel optoisolator from onsemi that accepts both AC and DC input, eliminating the need for a separate bridge rectifier when sensing AC mains zero-cross or line presence. The output is a phototransistor rated for 70V maximum collector-emitter voltage and 50mA continuous current per channel. Reinforced isolation of 5000Vrms supports safety barrier compliance for industrial controls, power-supply feedback loops, and PLC I/O modules where galvanic separation between high-voltage and low-voltage domains is mandatory.
CTR window and switching speed
Current transfer ratio is specified from 50% minimum to 150% maximum at a forward current of 1mA. This narrow CTR window reduces gain variation across reels compared to wider-bin parts, which simplifies feedback-loop compensation in isolated power supplies. Typical rise and fall times of 4µs and 3µs respectively are adequate for 50/60 Hz line-frequency sensing and low-speed digital isolation up to about 10 kbps. For faster serial interfaces like I²C or SPI, a logic-output optocoupler with higher data rate is needed.
Package and temperature range
Housed in a 4-SMD gull-wing package with a 4-SMD supplier device package designation. The gull-wing leads provide visual solder-joint inspection access and are compatible with standard reflow profiles for lead-free assembly. Rated for operation from -55°C to 105°C, covering most industrial and telecom enclosure environments. Not qualified to AEC-Q100 — for under-hood or chassis-mounted automotive applications, consider an AEC-grade optocoupler.
Sourcing and compliance status
No stock-holding claim is made; the part is sourced to order through our supply network.