2SC4551-L Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 60 V
• Collector-Base Voltage, max: 100 V
• Emitter-Base Voltage, max: 7 V
• Collector Current − Continuous, max: 10 A
• Collector Dissipation: 30 W
• DC Current Gain (h_fe): 150 to 300
• Transition Frequency, min: 140 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 2SC4551-L transistor can have a current gain of 150 to 300. The gain of the 2SC4551 will be in the range from 100 to 400, for the 2SC4551-K it will be in the range from 200 to 400, for the 2SC4551-M it will be in the range from 100 to 200.Sometimes the "2S" prefix is not marked on the package - the 2SC4551-L might only be marked "C4551-L".The complementary PNP transistor to the 2SC4551-L is the 2SA1743-L.You can replace the 2SC4551-L with the 2SC4552, 2SC4552-L, BD545A, BD545B, BD545C, BD807, BD809, BDT81, BDT81F, BDT83, BDT83F, BDT85, BDT85F, BDT87, BDT87F, D44H11, D44H11FP or D44H8.