2SD1906 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 80 V
• Collector-Base Voltage, max: 90 V
• Emitter-Base Voltage, max: 6 V
• Collector Current − Continuous, max: 5 A
• Collector Dissipation: 30 W
• DC Current Gain (h_fe): 70 to 280
• Transition Frequency, min: 20 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-262

Here is an image showing the pin diagram of this transistor.The 2SD1906 transistor can have a current gain of 70 to 280. The gain of the 2SD1906-Q will be in the range from 70 to 140, for the 2SD1906-R it will be in the range from 100 to 200, for the 2SD1906-S it will be in the range from 140 to 280.Sometimes the "2S" prefix is not marked on the package - the 2SD1906 might only be marked "D1906".The complementary PNP transistor to the 2SD1906 is the 2SB1270.The BDP951 (SOT-223) is the SMD version of the 2SD1906 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2SD1906 with the 2SD1907.