2SA1634-D Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -80 V
• Collector-Base Voltage, max: -80 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -4 A
• Collector Dissipation: 40 W
• DC Current Gain (h_fe): 60 to 120
• Transition Frequency, min: 12 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 2SA1634-D transistor can have a current gain of 60 to 120. The gain of the 2SA1634 will be in the range from 60 to 320, for the 2SA1634-E it will be in the range from 100 to 200, for the 2SA1634-F it will be in the range from 160 to 320.Sometimes the "2S" prefix is not marked on the package - the 2SA1634-D might only be marked "A1634-D".The BDP952 (SOT-223) is the SMD version of the 2SA1634-D transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2SA1634-D with the 2N6475, 2N6476, 2N6491, 2N6491G, 2SA1010, 2SA1010L, 2SA1077, 2SA1488A, 2SA1635, 2SA1635-D, 2SA1725, 2SA1726, 2SA769, 2SA771, 2SB1016, 2SB1017, 2SB1090, 2SB1367, 2SB1368, 2SB595, 2SB596, 2SB633, 2SB633-D, 2SB703, 2SB703-R, 2SB703A, 2SB703A-R, 2SB708, 2SB708-O, 2SB747, 2SB747-Q, 2SB762A, 2SB870, 2SB870-R, 2SB942A, 2SB945, 2SB945-R, 2SB946, 2SB946-R, 2SB995, 2SB996, BD244B, BD244C, BD538, BD540B, BD540C, BD544B, BD544C, BD546B, BD546C, BD710, BD712, BD744B, BD744C, BD800, BD802, BD810, BD910, BD912, BD952, BD954, BD956, BDT84, BDT84F, BDT86, BDT86F, BDT88, BDT88F, BDT94, BDT94F, BDT96, BDT96F, BDX78, D44C10, D44C11, D44C12, D45C10, D45C11, D45C12, D45H11, D45H11FP, KSA1010, KSA1010O, KSB1017, KSB596, KSB708, KSB708-O, KTB1367, KTB1368, MJE15029, MJE15029G, MJE15031, MJE15031G, MJF15031, MJF15031G, NTE153 or NTE292.