2SB557-O Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -120 V
• Collector-Base Voltage, max: -120 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -8 A
• Collector Dissipation: 80 W
• DC Current Gain (h_fe): 70 to 140
• Transition Frequency, min: 7 MHz
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: TO-3

Here is an image showing the pin diagram of this transistor.The 2SB557-O transistor can have a current gain of 70 to 140. The gain of the 2SB557 will be in the range from 40 to 140, for the 2SB557-R it will be in the range from 40 to 80.Sometimes the "2S" prefix is not marked on the package - the 2SB557-O might only be marked "B557-O".The complementary NPN transistor to the 2SB557-O is the 2SD427-O.You can replace the 2SB557-O with the 2SA1007, 2SA1007A, 2SA1041, 2SA1043, 2SA1072, 2SA1072A, 2SA1073, 2SA679, 2SA679-Y, 2SA745A, 2SA747, 2SA747A, 2SA908, 2SA909, 2SB554, 2SB554-O, 2SB555, 2SB555-O, 2SB556, 2SB556-O, 2SB600, 2SB696, 2SB697, 2SB697K, 2SB705, 2SB705A, 2SB705B, 2SB706, 2SB706A, 2SB722, 2SB723, MJ15002, MJ15002G, MJ15004 or MJ15004G.