2SD1805-S 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): 140 to 280
• 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-S transistor can have a current gain of 140 to 280. The gain of the 2SD1805 will be in the range from 100 to 400, for the 2SD1805-R it will be in the range from 100 to 200, 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-S might only be marked "D1805-S".The complementary PNP transistor to the 2SD1805-S is the 2SB1205-S.