This part is a kind of semiconductor called 2SD1297.

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 2SD1297 DESCRIPTION ·With TO-3PN package ·High DC current gain ·Low saturation voltage APPLICATIONS ·For audio frequency power amplifier and low speed high current switching industrial use PINNING PIN 1 2 3 Base Collector;connected to mounting base Emitter Fig.1 simplified outline (TO-3PN) and symbol DESCRIPTION Absolute maximum ratings (Ta=25 ) SYMBOL VCBO VCEO VEBO IC ICM IB PARAMETER Collector-base voltage Collector-emitter voltage Emitter-base voltage Collector current Collector current-peak Base current TC=25 PT Total power dissipation Ta=25 Tj Tstg Junction temperature Storage temperature 3.0 150 -55~150 CONDITIONS Open emitter Open base Open collector MAX 150 100 8 25 50 1.5 100 [ ... ]

2SD1297 PDF Datasheet Download