Isolation and switching profile for industrial signal paths
The FODM453 is a single-channel optocoupler from onsemi that delivers 3750Vrms galvanic isolation between a DC input LED and a phototransistor output. That isolation rating is typical for reinforced insulation in 250 VAC mains-referenced circuits — think PLC digital inputs, motor-drive feedback, or AC-DC converter secondary-side feedback loops. Switching is rated at 400 ns turn-on and 350 ns turn-off typical, which keeps the part clean for 1 MHz-ish pulse trains or PWM edges. The 20% to 50% current transfer ratio at 16 mA forward current gives a predictable saturation margin — if you bias the LED at 16 mA, the output transistor can sink up to 8 mA with a Vce well below 0.4 V across the industrial temperature range.
Package and footprint — 5-lead 6-SOIC
Housed in a 5-Mini-Flat package, the FODM453 uses a 6-SOIC (0.173-inch, 4.40 mm width) body with five leads — one lead position is omitted for pin-1 orientation. The surface-mount footprint is compatible with standard SOIC-6 land patterns; the 4.40 mm body width is narrower than the 7.5 mm wide SO-8, so check your existing optocoupler pad layout before dropping this in as a drop-in swap. The 85°C ceiling covers most industrial enclosures and outdoor telecom cabinets but stops short of under-hood automotive — if your BOM sees sustained 105°C ambient, you need a higher-temperature grade.