2SC3954 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 120 V
• Collector-Base Voltage, max: 120 V
• Emitter-Base Voltage, max: 3 V
• Collector Current − Continuous, max: 0.3 A
• Collector Dissipation: 8 W
• DC Current Gain (h_fe): 40 to 320
• Transition Frequency, min: 400 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-126F

Here is an image showing the pin diagram of this transistor.The 2SC3954 transistor can have a current gain of 40 to 320. The gain of the 2SC3954-C will be in the range from 40 to 80, for the 2SC3954-D it will be in the range from 60 to 120, for the 2SC3954-E it will be in the range from 100 to 200, for the 2SC3954-F it will be in the range from 160 to 320.Sometimes the "2S" prefix is not marked on the package - the 2SC3954 might only be marked "C3954".The complementary PNP transistor to the 2SC3954 is the 2SA1539.You can replace the 2SC3954 with the 2SC3599.