This part is a kind of semiconductor called BUZ77B.

Function of this product has SIPMOS Power Transistor (N channel Enhancement mode Avalanche-rated).

Manufacturers : Siemens Semiconductor Group

Image and pinout :

Some of the text within the PDF file :

BUZ 77 B SIPMOS ® Power Transistor • N channel • Enhancement mode • Avalanche-rated Pin 1 G Pin 2 D Pin 3 S Type BUZ 77 B VDS 600 V ID 2.9 A RDS(on) 3.5 Ω Package TO-220 AB Ordering Code C67078-S1320-A5 Maximum Ratings Parameter Continuous drain current Symbol Values 2.9 Unit A ID IDpuls 11.5 TC = 29 °C Pulsed drain current TC = 25 °C Avalanche current,limited by Tjmax Avalanche energy,periodic limited by Tjmax Avalanche energy, single pulse IAR EAR EAS 2.7 5 mJ ID = 2.7 A, VDD = 50 V, RGS = 25 Ω L = 45.3 mH, Tj = 25 °C Gate source voltage Power dissipation 180 VGS Ptot ± 20 75 V W TC = 25 °C Operating temperature Storage temperature Thermal resistance, chip case Thermal resistance, chip to ambient DIN humidity category, DIN 40 040 IEC climatic categor [ ... ]

BUZ77B PDF Datasheet Download