2SD855 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 60 V
• Collector-Base Voltage, max: 60 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 1 A
• Collector Dissipation: 30 W
• DC Current Gain (h_fe): 40 to 250
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-220

Here is an image showing the pin diagram of this transistor.The 2SD855 transistor can have a current gain of 40 to 250. The gain of the 2SD855-Q will be in the range from 70 to 150, for the 2SD855-R it will be in the range from 40 to 90.Sometimes the "2S" prefix is not marked on the package - the 2SD855 might only be marked "D855".The complementary PNP transistor to the 2SD855 is the 2SB760.The BCP55 (SOT-223) is the SMD version of the 2SD855 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2SD855 with the 2SC1826, 2SC1985, 2SC1986, 2SC2075, 2SC3179, 2SC3851, 2SC3851A, 2SD1267, 2SD1267A, 2SD1274, 2SD1274A, 2SD1274B, 2SD313, 2SD613, 2SD823, 2SD856, 2SD856A, 2SD857, 2SD857A, BD203, BD239A, BD239B, BD239C, BD241A, BD241B, BD241C, BD243A, BD243B, BD243C, BD303, BD535, BD537, BD539A, BD539B, BD539C, BD539D, BD797, BD799, BD801, BD807, BD809, BD935, BD935F, BD937, BD937F, BD939, BD939F, BD941, BD941F, BD949, BD951, BD953, BD955, BDT29A, BDT29B, BDT29C, BDT81, BDT81F, BDT83, BDT83F, BDT85, BDT85F, BDT87, BDT87F, BDX77, MJE15028, MJE15028G, TIP41D or TIP42D.