2SD401A-K Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 150 V
• Collector-Base Voltage, max: 200 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 2 A
• Collector Dissipation: 25 W
• DC Current Gain (h_fe): 100 to 200
• Transition Frequency, min: 5 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 2SD401A-K transistor can have a current gain of 100 to 200. The gain of the 2SD401A will be in the range from 40 to 200, for the 2SD401A-L it will be in the range from 60 to 120, for the 2SD401A-M it will be in the range from 40 to 80.Sometimes the "2S" prefix is not marked on the package - the 2SD401A-K might only be marked "D401A-K".The complementary PNP transistor to the 2SD401A-K is the 2SB546A-K.You can replace the 2SD401A-K with the 2SC4381, 2SC4382, 2SC4883, 2SC4883A, 2SC5171, 2SD1138, 2SD1138C, 2SD1264, 2SD1264-P, 2SD1264A, 2SD1264A-P, 2SD401, 2SD402, 2SD610, 2SD610-Q, 2SD772, 2SD772A, 2SD772B, 2SD792, 2SD792A, 2SD792B, KTD2061, MJE15030, MJE15030G, MJE15032, MJE15032G, MJF15030, MJF15030G, NTE375, TIP41F or TIP42F.