This is one of the semiconductor types. This part name is K3878.
This product has Field Effect Transistor functions.
Manufacturers of product is Toshiba.
Image and pinout :
K3878 PDF Datasheet
Some of the text files within the PDF file
2SK3878 TOSHIBA Field Effect Transistor Silicon N-Channel MOS Type (π- MOSIV) 2SK3878 Switching Regulator Applications • • • • Low drain-source ON-resistance: RDS (ON) = 1.0 Ω (typ.) High forward transfer admittance: ⎪Yfs⎪ = 7.0 S (typ.) Low leakage current: IDSS = 100 μA (max) (VDS = 720 V) Enhancement model: Vth = 2.0 to 4.0 V (VDS = 10 V, ID = 1 mA) Unit: mm Absolute Maximum Ratings (Ta = 25°C) Characteristic Drain-source voltage Drain-gate voltage (RGS = 20 kΩ) Gate-source voltage Drain current DC Pulse (Note 1) (Note 1) Symbol VDSS VDGR VGSS ID IDP PD EAS IAR EAR Tch Tstg Rating 900 900 ±30 9 27 150 778 9 15 150 −55 to 150 Unit V V V A W mJ A mJ °C °C 1. GATE 2. DRAIN (HEATSINK) 3. SOURCE Drain power dissipation (Tc = 25°C) Single pulse avalanche energy (Note 2) Avalanche current Repetitive avalanche energy (Note 3) Channel temperature Storage temperature range JEDEC JEITA TOSHIBA ― SC-65 2−16C1B Weight: 4.6 g (typ.) Note: Using continuously under [ … ]
Please refer to the file for details.