This part is a kind of semiconductor called 2SK3133.
Function of this product has Silicon N Channel MOS FET High Speed Power Switching.
Manufacturers : Hitachi Semiconductor
Image and pinout :

Some of the text within the PDF file :
2SK3133(L),2SK3133(S) Silicon N Channel MOS FET High Speed Power Switching ADE-208-720 (Z) Target Specification 1st. Edition February 1999 Features • Low on-resistance R DS(on) = 7 mΩ typ. • Low drive current • 4 V gate drive device can be driven from 5 V source Outline LDPAK 4 4 D 1 1 2 3 G 2 3 1. Gate 2. Drain 3. Source 4. Drain S 2SK3133(L),2SK3133(S) Absolute Maximum Ratings (Ta = 25°C) Item Drain to source voltage Gate to source voltage Drain current Drain peak current Body-drain diode reverse drain current Channel dissipation Channel temperature Storage temperature Note: 1. PW ≤ 10 µs, duty cycle ≤ 1% 2. Value at Tc = 25°C Symbol VDSS VGSS ID I D(pulse) I DR Pch Tch Tstg Note 2 Note 1 Ratings 30 ±20 50 200 50 50 150 –55 to +150 Unit V V A A A W °C °C [ ... ]
2SK3133 PDF Datasheet Download
