2SD400 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 25 V
• Collector-Base Voltage, max: 25 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 1 A
• Collector Dissipation: 0.9 W
• DC Current Gain (h_fe): 60 to 560
• Transition Frequency, min: 180 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 2SD400 transistor can have a current gain of 60 to 560. The gain of the 2SD400D will be in the range from 60 to 120, for the 2SD400E it will be in the range from 100 to 200, for the 2SD400F it will be in the range from 160 to 320, for the 2SD400G it will be in the range from 280 to 560.Sometimes the "2S" prefix is not marked on the package - the 2SD400 might only be marked "D400".The complementary PNP transistor to the 2SD400 is the 2SB544.You can replace the 2SD400 with the BD201, BD239, BD241, BD243, BD301, BD533, BD539, BD543, BD545, BD733, BD735, BD737, BD795 or BDT29.