Isolation and switching profile
The 4N28TM: Typical turn-on and turn-off times are 2µs each, which puts it in the medium-speed band for optocouplers — fine for 10 kHz-ish switching or status feedback, but not for high-speed data or gate-drive applications where propagation delay skew matters.
Package and rework reality
The 6-DIP outline has a clear pin-1 indicator (a dimple or bevel at the end of the body), so orientation is unambiguous under magnification. No exposed paddle or thermal pad to worry about — just clip the leads, lift the part, and wick the holes clean.
Lifecycle and sourcing posture
Quantities are lot-specific and confirmed at RFQ; no stock-holding claim is made here.