400 V / 4 A NPN — what it handles and where it goes
Packaged in a through-hole TO-220-3, it is designed for medium-voltage switching applications such as offline flyback converters, motor drive snubbers, and general-purpose power switching where a single NPN device with a metal-tab heatsink interface is needed. The 500 mV Vce saturation at 3.5 A keeps conduction losses manageable in hard-switched topologies.
ROHS3 compliant.
Package and mounting — TO-220-3 through-hole
The TO-220-3 package is a through-hole form factor with a metal tab for bolting to a heatsink. The collector is internally connected to the tab, so an insulating pad and washer are needed if the heatsink is at chassis ground. The 150°C junction temperature rating sets the thermal derating curve — size the heatsink to keep the junction below that limit at the expected ambient and load.