This part is a kind of semiconductor called 2SK1254.
Function of this product has Silicon N-Channel MOS FET.
Manufacturers : Hitachi Semiconductor
Image and pinout :
Some of the text within the PDF file :
2SK1254(L), 2SK1254(S) Silicon N-Channel MOS FET Application High speed power switching Features • Low on-resistance • High speed switching • 4 V gate drive device Can be driven from 5 V source • Suitable for motor drive, DC-DC converter, power switch and solenoid drive Outline DPAK-1 4 4 1 1 D G 1. Gate 2. Drain 3. Source 4. Drain S 2 3 2 3 2SK1254(L), 2SK1254(S) Absolute Maximum Ratings (Ta = 25°C) Item Drain to source voltage Gate to source voltage Drain current Drain peak current Body to drain diode reverse drain current Channel dissipation Channel temperature Storage temperature Notes: 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 2 1 Ratings 120 ±20 3 12 3 20 150 –55 to +150 Unit V V A A A W °C [ ... ]