This part is a kind of semiconductor called 2SD2012.

Function of this product has NPN SILICON POWER TRANSISTOR.

Manufacturers : STMicroelectronics

Image and pinout :

Some of the text within the PDF file :

® 2SD2012 NPN SILICON POWER TRANSISTOR s s s HIGH DC CURRENT GAIN LOW SATURATION VOLTAGE INSULATED PACKAGE FOR EASY MOUNTING APPLICATIONS GENERAL PURPOSE POWER AMPLIFIERS s GENERAL PURPOSE SWITCHING s DESCRIPTION The 2SD2012 is a silicon NPN power transistor housed in TO-220F insulated package. It is inteded for power linear and switching applications. 3 1 2 TO-220F INTERNAL SCHEMATIC DIAGRAM ABSOLUTE MAXIMUM RATINGS Symbol V CBO V CEO V EBO IC I CM IB P tot Visol T stg Tj Parameter Collector-Base Voltage (I E = 0) Collector-Emitter Voltage (I B = 0) Emitter-Base Voltage (I C = 0) Collector Current Collector Peak Current (t p < 5 ms) Base Current Total Dissipation at T c ≤ 25 o C Insulation Withstand Voltage (RMS) from All Three Leads to Exernal Heatsink St [ ... ]

2SD2012 PDF Datasheet Download