This part is a kind of semiconductor called STU446S.

Function of this product has N-Channel Logic Level Enhancement Mode Field Effect Transistor.

Manufacturers : SamHop Microelectronics

Image and pinout :

Some of the text within the PDF file :

Green Product STU/D446S Ver 2.0 S a mHop Microelectronics C orp. N-Channel Logic Level Enhancement Mode Field Effect Transistor PRODUCT SUMMARY V DSS 40V ID 38A R DS(ON) (m Ω) Max 16.5 @ VGS=10V 28 @ VGS=4.5V FEATURES Super high dense cell design for low R DS(ON). Rugged and reliable. TO-252 and TO-251 Package. Pb Free and Halogan Free. G S G D S STU SERIES TO - 252AA( D - PAK ) STD SERIES TO - 251 ( I - PAK ) ABSOLUTE MAXIMUM RATINGS ( T A=25 °C unless otherwise noted ) Symbol VDS VGS ID IDM EAS PD TJ, TSTG Parameter Drain-Source Voltage Gate-Source Voltage Drain Current-Continuous -Pulsed b d a Limit 40 ±20 TC=25°C TC=70°C 38 30 111 64 TC=25°C TC=70°C 42 27 -55 to 150 Units V V A A A mJ W W °C Single Pulse Avalanche Energy Maximum Power Dissipation a Operating Jun [ ... ]

STU446S PDF Datasheet Download