950 V MDmesh K5 MOSFET in a surface-mount H2Pak-2
It is built with ST's MDmesh technology, which reduces on-resistance per silicon area for high-voltage switching. The 1.25 Ohm maximum Rds(on) at 3 A and 10 V drive keeps conduction losses manageable in a 150 W-class flyback converter or PFC stage.
These numbers tell the drive circuit designer how much current the gate driver must supply to hit the target switching frequency.
Package and thermal path for the layout engineer
The H2Pak-2 package (TO-263-3, D²Pak with 2 leads plus tab) is a surface-mount D²Pak variant with a large exposed metal tab on the bottom.
It is ROHS3 compliant.