This part is a kind of semiconductor called BD649.

Function of this product has (BD645 - BD651) NPN SILICON POWER DARLINGTONS.

Manufacturers : Bourns Electronic Solutions

Image and pinout :

Some of the text within the PDF file :

BD645, BD647, BD649, BD651 NPN SILICON POWER DARLINGTONS ● ● ● ● Designed for Complementary Use with BD646, BD648, BD650 and BD652 62.5 W at 25°C Case Temperature 8 A Continuous Collector Current Minimum hFE of 750 at 3V, 3 A B C E TO-220 PACKAGE (TOP VIEW) 1 2 3 Pin 2 is in electrical contact with the mounting base. MDTRACA absolute maximum ratings at 25°C case temperature (unless otherwise noted) RATING BD645 Collector-base voltage (IE = 0) BD647 BD649 BD651 BD645 Collector-emitter voltage (IB = 0) BD647 BD649 BD651 Emitter-base voltage Continuous collector current Peak collector current (see Note 1) Continuous base current Continuous device dissipation at (or below) 25°C case temperature (see Note 2) Continuous device dissipation at (or below) 25°C [ ... ]

BD649 PDF Datasheet Download