This part is a kind of semiconductor called K3404.

Function of this product has 2SK3404.

Manufacturers : NEC

Image and pinout :

Some of the text within the PDF file :

DATA SHEET MOS FIELD EFFECT TRANSISTOR 2SK3404 SWITCHING N-CHANNEL POWER MOS FET INDUSTRIAL USE DESCRIPTION The 2SK3404 is N-Channel MOS FET device that features a low on-state resistance and excellent switching characteristics, designed for low voltage high current applications such as DC/DC converter with synchronous rectifier. ORDERING INFORMATION PART NUMBER 2SK3404 2SK3404-ZK 2SK3404-ZJ PACKAGE TO-220AB TO-263(MP-25ZK) TO-263(MP-25ZJ) FEATURES • 4.5-V drive available • Low on-state resistance RDS(on)1 = 14 mΩ MAX. (VGS = 10 V, ID = 20 A) • Low gate charge QG = 25 nC TYP. (ID = 40 A, VDD = 24 V, VGS = 10 V) • Built-in gate protection diode • Surface mount device available ABSOLUTE MAXIMUM RATINGS (TA = 25°C) Drain to Source Voltage (VGS = 0 V) Gate to Source Voltage [ ... ]

K3404 PDF Datasheet Download