2SD1891-Q Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 90 V
• Collector-Base Voltage, max: 110 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 4 A
• Collector Dissipation: 40 W
• DC Current Gain (h_fe): 8000 to 30000
• Transition Frequency, min: 20 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-220F

Here is an image showing the pin diagram of this transistor.The 2SD1891-Q transistor can have a current gain of 8000 to 30000. The gain of the 2SD1891 will be in the range from 5000 to 30000, for the 2SD1891-P it will be in the range from 5000 to 15000.Sometimes the "2S" prefix is not marked on the package - the 2SD1891-Q might only be marked "D1891-Q".The complementary PNP transistor to the 2SD1891-Q is the 2SB1251-Q.You can replace the 2SD1891-Q with the 2SD1195, 2SD1196, 2SD1829, 2SD1830, 2SD1892, 2SD1892-Q, 2SD2241, 2SD2495, 2SD772, 2SD792, 2SD823, BD243C, BD539C, BD539D, BD543C, BD545C, BD649, BD651, BD801, BD901, BD953, BD955, BDT61B, BDT61C, BDT63B, BDT63C, BDT65B, BDT65C, BDT85, BDT85F, BDT87, BDT87F, BDW42, BDW42G, BDW43, BDX33C, BDX33CG, BDX33D, BDX53C, BDX53CG, BDX53D, BDX53E, BDX53F, MJE15028, MJE15028G, MJE15030, MJE15030G, MJF122, MJF122G, MJF15030, MJF15030G, TIP122, TIP122G, TIP142T, TIP41D, TIP41E, TIP41F, TIP42D, TIP42E or TIP42F.