The STP12N60M2: Rated at 600 V drain-to-source with a continuous drain current of 9 A at 25 °C case temperature, this part fits offline flyback converters, PFC stages, and auxiliary power supplies where the bus voltage sits at 400 VDC. The 450 mOhm maximum on-resistance at 4.5 A, 10 V gate drive gives a conduction loss of roughly 2 W at that current — manageable in a TO-220 package with 85 W maximum dissipation, but derating for ambient temperature is necessary above 100 °C junction.
Gate charge and switching — 16 nC keeps the driver simple
With a typical gate charge of 16 nC at 10 V, the gate drive power at 100 kHz switching is only about 16 mW — a standard bootstrap driver or a small PWM controller can handle it without an external driver stage. Input capacitance is 538 pF at 100 V drain bias.