This part is a kind of semiconductor called 2SD1691.

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 2SD1691 DESCRIPTION ·With TO-126 package ·Complement to type 2SB1151 ·Low saturation voltage ·High total power dissipation:PT=1.3W ·Large current capability and wide SOA APPLICATIONS ·DC-DC converter ·Driver of solenoid or motor PINNING PIN 1 2 3 DESCRIPTION Emitter Collector;connected to mounting base Base Absolute maximum ratings(Ta=25 ) SYMBOL VCBO VCEO VEBO IC ICM IB PARAMETER Collector-base voltage Collector-emitter voltage Emitter-base voltage Collector current (DC) Collector current-Peak Base current Ta=25 PD Total power dissipation TC=25 Tj Tstg Junction temperature Storage temperature 20 150 -55~150 CONDITIONS Open emitter Open base Open collector VALUE 60 60 7 5 8 1 1.3 W U [ ... ]

2SD1691 PDF Datasheet Download