2SD425 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 140 V
• Collector-Base Voltage, max: 140 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 12 A
• Collector Dissipation: 100 W
• DC Current Gain (h_fe): 40 to 140
• Transition Frequency, min: 5 MHz
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: TO-3

Here is an image showing the pin diagram of this transistor.The 2SD425 transistor can have a current gain of 40 to 140. The gain of the 2SD425-O will be in the range from 70 to 140, for the 2SD425-R it will be in the range from 40 to 80.Sometimes the "2S" prefix is not marked on the package - the 2SD425 might only be marked "D425".The complementary PNP transistor to the 2SD425 is the 2SB555.You can replace the 2SD425 with the 2SC2428, 2SD424, 2SD733, 2SD733K, 2SD753, MJ15001, MJ15001G, MJ15003 or MJ15003G.