2SB1274S Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -60 V
• Collector-Base Voltage, max: -60 V
• Emitter-Base Voltage, max: -6 V
• Collector Current − Continuous, max: -3 A
• Collector Dissipation: 20 W
• DC Current Gain (h_fe): 140 to 280
• Transition Frequency, min: 100 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 2SB1274S transistor can have a current gain of 140 to 280. The gain of the 2SB1274 will be in the range from 70 to 280, for the 2SB1274Q it will be in the range from 70 to 120, for the 2SB1274R it will be in the range from 100 to 200.Sometimes the "2S" prefix is not marked on the package - the 2SB1274S might only be marked "B1274S".The complementary NPN transistor to the 2SB1274S is the 2SD1913S.The BDP950 (SOT-223) is the SMD version of the 2SB1274S transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2SB1274S with the 2SA1262, 2SA1288, 2SA1288-S, 2SA1289, 2SA1289-S, 2SA1290, 2SA1290-S, 2SA1291, 2SA1291-S, 2SA1469, 2SA1469-S, 2SA1470, 2SA1470-S, 2SA1471, 2SA1471-S, 2SA1488, 2SA1488A, 2SA1634, 2SA1635, 2SA1742, 2SA1743, 2SA1744, 2SA770, 2SA771, 2SB1133, 2SB1133-S, 2SB1187, 2SB1375, 2SB1565, 2SB507, 2SB633, 2SB834, 2SB858, BD204, BD242A, BD242B, BD242C, BD244A, BD244B, BD244C, BD304, BD536, BD538, BD540A, BD540B, BD540C, BD544A, BD544B, BD544C, BD546A, BD546B, BD546C, BD798, BD800, BD802, BD808, BD810, BD950, BD952, BD954, BD956, BDT82, BDT82F, BDT84, BDT84F, BDT86, BDT86F, BDT88, BDT88F, BDX78, D44C10, D44C11, D44C12, D44C7, D44C8, D44C9, D45C10, D45C11, D45C12, D45C7, D45C8, D45C9, D45H11, D45H11FP, D45H8, KSB1366, KTA1036, KTB988, MJE15029 or MJE15029G.