N-Channel MOSFET, 51 A, 250 V, 3-Pin TO-220AB onsemi FDP51N25

UniFET™ MOSFET is Fairchild Semiconductor's high voltage MOSFET family. It has the smallest on-state resistance among the planar MOSFETs, and also provides superior switching performance and higher avalanche energy strength. In addition, the internal gate-source ESD diode allows UniFET-II™ MOSFET to withstand over 2000V HBM surge stress.
UniFET™ MOSFETs are suitable for switching power converter applications, such as power factor correction (PFC), flat panel display (FPD) TV power, ATX (Advanced Technology eXtended) and electronic lamp ballasts.

MOSFET Transistors, ON Semi

ON Semi offers a substantial portfolio of MOSFET devices that includes high-voltage (>250V) and low-voltage (<250V) types. The advanced silicon technology provides smaller die sizes, which it is incorporated into multiple industry-standard and thermally-enhanced packages.
ON Semi MOSFETs provide superior design reliability from reduced voltage spikes and overshoot, to lower junction capacitance and reverse recovery charge, to elimination of additional external components to keep systems up and running longer.