2SD1805 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 20 V
• Collector-Base Voltage, max: 25 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 5 A
• Collector Dissipation: 10 W
• DC Current Gain (h_fe): 100 to 400
• Transition Frequency, min: 320 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-251

Here is an image showing the pin diagram of this transistor.The 2SD1805 transistor can have a current gain of 100 to 400. The gain of the 2SD1805-R will be in the range from 100 to 200, for the 2SD1805-S it will be in the range from 140 to 280, for the 2SD1805-T it will be in the range from 200 to 400.Sometimes the "2S" prefix is not marked on the package - the 2SD1805 might only be marked "D1805".The complementary PNP transistor to the 2SD1805 is the 2SB1205.