BDT81 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 60 V
• Collector-Base Voltage, max: 60 V
• Emitter-Base Voltage, max: 7 V
• Collector Current − Continuous, max: 15 A
• Collector Dissipation: 125 W
• DC Current Gain (h_fe): 40
• Transition Frequency, min: 10 MHz
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: TO-220

Here is an image showing the pin diagram of this transistor.The complementary PNP transistor to the BDT81 is the BDT82.You can replace the BDT81 with the 2SC4552, 2SC4552-K, 2SC4552-L, 2SC4552-M, BD545A, BD545B, BD545C, BDT81F, BDT83, BDT83F, BDT85, BDT85F, BDT87, BDT87F, BDW40, BDW41, BDW41G, BDW42, BDW42G, BDW43, MJF6388 or MJF6388G.