This part is a kind of semiconductor called BD677.

Function of this product has DARLINGTON POWER TRANSISTORS NPN SILICON.

Manufacturers : ON Semiconductor

Image and pinout :

Some of the text within the PDF file :

BD675, BD675A, BD677, BD677A, BD679, BD679A, BD681 BD681 is a Preferred Device Plastic Medium−Power Silicon NPN Darlingtons This series of plastic, medium−power silicon NPN Darlington transistors can be used as output devices in complementary general−purpose amplifier applications. Features http://onsemi.com • High DC Current Gain: • • • • hFE = 750 (Min) @ IC = 1.5 and 2.0 Adc Monolithic Construction BD675, 675A, 677, 677A, 679, 679A, 681 are complementary with BD676, 676A, 678, 678A, 680, 680A, 682 BD677, 677A, 679, 679A are equivalent to MJE 800, 801, 802, 803 Pb−Free Packages are Available* 4.0 AMPERES POWER TRANSISTORS NPN SILICON 60, 80, 100 VOLTS, 40 WATTS ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎ [ ... ]

BD677 PDF Datasheet Download