20 Mbps digital isolation with reinforced 5 kVrms barrier
The onsemi FOD8173T is a single-channel digital optoisolator that pushes 20 Mbps through a 5000 Vrms reinforced isolation barrier — fast enough for Profibus, CAN, or RS-485 lines where galvanic separation is a safety or noise requirement.
CMTI and propagation delay — the timing-critical specs
Common-mode transient immunity is 20 kV/µs minimum — the part will not falsely toggle its output when a motor drive or switching supply slams 20 kV/µs across the barrier. That figure is the floor, not a typical, so it holds across temperature and supply voltage. Propagation delay is 55 ns max, symmetric between low-to-high and high-to-low transitions. Symmetry means the output pulse width matches the input pulse width within the delay budget — no duty-cycle distortion beyond that 55 ns window.
Wide-body SOIC for creepage and clearance
The 6-SOIC package is the 6.80 mm wide-body variant — the extra width (vs a standard 3.9 mm SOIC) gives 8 mm creepage distance across the package surface, which is what supports the 5000 Vrms isolation rating in a surface-mount assembly. Supplier device package is 6-SOP, which lands on the same PCB footprint as a standard SOIC-6 wide-body. No special pad pattern beyond what the datasheet recommends for the 6.80 mm body.
Active lifecycle — no EOL watch needed
Base product number is FOD8173, so the FOD8173T variant (tube packaging) shares the same die and qualification as the tape-and-reel sibling. No difference in the isolation or speed ratings between the packaging options.