2SC3781 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 120 V
• Collector-Base Voltage, max: 120 V
• Emitter-Base Voltage, max: 4 V
• Collector Current − Continuous, max: 0.4 A
• Collector Dissipation: 15 W
• DC Current Gain (h_fe): 40 to 320
• Transition Frequency, min: 500 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-220

Here is an image showing the pin diagram of this transistor.The 2SC3781 transistor can have a current gain of 40 to 320. The gain of the 2SC3781-C will be in the range from 40 to 80, for the 2SC3781-D it will be in the range from 60 to 120, for the 2SC3781-E it will be in the range from 100 to 200, for the 2SC3781-F it will be in the range from 160 to 320.Sometimes the "2S" prefix is not marked on the package - the 2SC3781 might only be marked "C3781".The complementary PNP transistor to the 2SC3781 is the 2SA1475.You can replace the 2SC3781 with the 2SD401, 2SD402, 2SD772, 2SD772A, 2SD792, 2SD792A, BD539D, BD955, BDT87, BDT87F, MJE15028, MJE15028G, MJE15030, MJE15030G, MJF15030, MJF15030G, TIP41D, TIP41E, TIP41F, TIP42D, TIP42E or TIP42F.