2SA1908 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -120 V
• Collector-Base Voltage, max: -120 V
• Emitter-Base Voltage, max: -6 V
• Collector Current − Continuous, max: -8 A
• Collector Dissipation: 75 W
• DC Current Gain (h_fe): 50 to 180
• Transition Frequency, min: 20 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-3PF

Here is an image showing the pin diagram of this transistor.The 2SA1908 transistor can have a current gain of 50 to 180. The gain of the 2SA1908-O will be in the range from 50 to 100, for the 2SA1908-P it will be in the range from 70 to 140, for the 2SA1908-Y it will be in the range from 90 to 180.Sometimes the "2S" prefix is not marked on the package - the 2SA1908 might only be marked "A1908".The complementary NPN transistor to the 2SA1908 is the 2SC5100.You can replace the 2SA1908 with the 2SA1673, 2SA1860, 2SA1909, 2SB1057 or FJAF4210.