2SC3781-D 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): 60 to 120
• 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-D transistor can have a current gain of 60 to 120. The gain of the 2SC3781 will be in the range from 40 to 320, for the 2SC3781-C it will be in the range from 40 to 80, 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-D might only be marked "C3781-D".The complementary PNP transistor to the 2SC3781-D is the 2SA1475-D.You can replace the 2SC3781-D with the 2N6474, 2N6477, 2N6478, 2SC1448, 2SC2073, 2SC2073A, 2SC2275, 2SC2275-R, 2SC2275A, 2SC2275A-R, 2SC2336, 2SC2336-R, 2SC2336A, 2SC2336A-R, 2SC2344, 2SC2344D, 2SC2527, 2SC2528, 2SC3296, 2SC4381, 2SC4382, 2SC4883, 2SC4883A, 2SC5248, 2SC5248-D, 2SD1138, 2SD1138B, 2SD1264, 2SD1264-Q, 2SD1264A, 2SD1264A-Q, 2SD1562, 2SD1562-D, 2SD1562A, 2SD1562A-D, 2SD1763A, 2SD1763A-E, 2SD363, 2SD401, 2SD401A, 2SD401A-L, 2SD402, 2SD610, 2SD610-R, 2SD772, 2SD772A, 2SD792, 2SD792A, BD539D, BD941, BD941F, BD955, BDT87, BDT87F, KSC2073, KSC3296, KSD363, MJE15028, MJE15028G, MJE15030, MJE15030G, MJF15030, MJF15030G, NTE291, TIP41D, TIP41E, TIP41F, TIP42D, TIP42E or TIP42F.