2SB1557 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -140 V
• Collector-Base Voltage, max: -140 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -7 A
• Collector Dissipation: 70 W
• DC Current Gain (h_fe): 5000 to 30000
• Transition Frequency, min: 30 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-3P

Here is an image showing the pin diagram of this transistor.The 2SB1557 transistor can have a current gain of 5000 to 30000. The gain of the 2SB1557-A will be in the range from 5000 to 12000, for the 2SB1557-B it will be in the range from 9000 to 18000, for the 2SB1557-C it will be in the range from 15000 to 30000.Sometimes the "2S" prefix is not marked on the package - the 2SB1557 might only be marked "B1557".The complementary NPN transistor to the 2SB1557 is the 2SD2386.You can replace the 2SB1557 with the 2SA1106, 2SB1555, 2SB1556, 2SB1558, 2SB1559, 2SB1560 or BDV66D.