The STL31N65M5 is a 650 V N-channel MOSFET from STMicroelectronics' MDmesh V series. At 11 A, that is about 19.6 W dissipated in the channel — the 125 W case-rated power dissipation means the die can handle it with adequate heatsinking, but the 2.8 W ambient rating flags that the board-level thermal design is what limits continuous current in a real enclosure.
Gate charge and switching — 45 nC at 10 V
Total gate charge is 45 nC at 10 V. That is moderate for a 650 V 15 A device — the driver sees about 4.5 mA per 100 kHz of switching frequency from the gate alone. The 1865 pF input capacitance at 100 V confirms the Miller plateau is manageable; a standard 1 A gate driver will switch this part cleanly into the 100–200 kHz range without excessive cross-conduction. Running at 5 V would leave the channel partially enhanced, increasing conduction losses. The ±25 V Vgs max gives margin for gate ringing on a hard-switched half-bridge.
PowerFlat 8x8 HV — footprint and thermal path
The PowerFlat 8x8 HV package is a surface-mount 8-lead VDFN with an exposed die pad on the bottom. The 125 W case-rated power dissipation requires a thermal path through the pad. The package is ROHS3 compliant and surface-mount.
For a BOM line, that means no last-time-buy planning needed. The part is ROHS3 compliant.