The CNY1743SD is officially obsolete per onsemi's lifecycle status. No stock-holding claim; availability verified per order.
Isolation and signal transfer
Rated for 5300Vrms isolation — this is the reinforced insulation class for mains-separated circuits in industrial PSUs, motor drives, and PLC I/O modules. Current transfer ratio spans 160% to 320% at 10 mA forward current — the wide min-max spread means the downstream logic must tolerate the full range without false triggering or saturation. Output transistor is rated for 70 V collector-emitter and 50 mA continuous current, with a 300 mV Vce(sat) max — suitable for switching 24 V PLC inputs or 5 V logic rails at moderate speed.
6-SMD gull wing package — the leads are formed outward for visual solder inspection and rework with a standard iron. No hot-air station needed for removal. Supplied in tape and reel (TR) — compatible with automated pick-and-place. The 6-SMD footprint is shared across the CNY174 family; a board already laid out for a through-hole DIP-6 variant will need a pad pattern change.