This part is a kind of semiconductor called 2SD401.

Function of this product has SILICON POWER TRANSISTOR.

Manufacturers : SavantIC

Image and pinout :

Some of the text within the PDF file :

SavantIC Semiconductor Product Specification Silicon NPN Power Transistors 2SD401 DESCRIPTION ·With TO-220C package ·Complement to type 2SB546 ·Collector current IC=2A ·Collector-base voltage VCBO=200V APPLICATIONS ·For use in general purpose power amplifier,vertical output application PINNING PIN 1 2 3 Base Collector;connected to mounting base Emitter DESCRIPTION Absolute maximum ratings (Ta=25 ) SYMBOL VCBO VCEO VEBO IC PC Tj Tstg PARAMETER Collector-base voltage Collector-emitter voltage Emitter-base voltage Collector current Collector power dissipation Junction temperature Storage temperature TC=25 CONDITIONS Open emitter Open base Open collector VALUE 200 150 5 2 25 150 -55~150 UNIT V V V A W SavantIC Semiconductor Product Specification Silicon NPN P [ ... ]

2SD401 PDF Datasheet Download