2SB1231 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -100 V
• Collector-Base Voltage, max: -110 V
• Emitter-Base Voltage, max: -6 V
• Collector Current − Continuous, max: -25 A
• Collector Dissipation: 120 W
• DC Current Gain (h_fe): 50 to 140
• 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 2SB1231 transistor can have a current gain of 50 to 140. The gain of the 2SB1231-P will be in the range from 50 to 100, for the 2SB1231-Q it will be in the range from 70 to 140.Sometimes the "2S" prefix is not marked on the package - the 2SB1231 might only be marked "B1231".The complementary NPN transistor to the 2SB1231 is the 2SD1841.You can replace the 2SB1231 with the 2SB1232, BD250C or TIP36CA.