2SD1253A-R Bipolar Transistor

• Type: NPN
• 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): 40 to 90
• Transition Frequency, min: 20 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-252

Here is an image showing the pin diagram of this transistor.The 2SD1253A-R transistor can have a current gain of 40 to 90. The gain of the 2SD1253A will be in the range from 40 to 250, for the 2SD1253A-P it will be in the range from 120 to 250, for the 2SD1253A-Q it will be in the range from 70 to 150.Sometimes the "2S" prefix is not marked on the package - the 2SD1253A-R might only be marked "D1253A-R".The BDP951 (SOT-223) is the SMD version of the 2SD1253A-R transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.