2SA1635 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: 30 W
• DC Current Gain (h_fe): 60 to 320
• Transition Frequency, min: 12 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 2SA1635 transistor can have a current gain of 60 to 320. The gain of the 2SA1635-D will be in the range from 60 to 120, for the 2SA1635-E it will be in the range from 100 to 200, for the 2SA1635-F it will be in the range from 160 to 320.Sometimes the "2S" prefix is not marked on the package - the 2SA1635 might only be marked "A1635".The complementary NPN transistor to the 2SA1635 is the 2SC4008.The BDP952 (SOT-223) is the SMD version of the 2SA1635 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2SA1635 with the 2SA1488A, 2SA1634, 2SA771, 2SB633, BD244B, BD244C, BD538, BD540B, BD540C, BD544B, BD544C, BD546B, BD546C, BD800, BD802, BD810, BD952, BD954, BD956, BDT84, BDT84F, BDT86, BDT86F, BDT88, BDT88F, BDX78, D44C10, D44C11, D44C12, D45C10, D45C11, D45C12, D45H11, D45H11FP, MJE15029, MJE15029G, MJE15031, MJE15031G, MJF15031 or MJF15031G.