2SC3951-E Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 70 V
• Collector-Base Voltage, max: 80 V
• Emitter-Base Voltage, max: 3 V
• Collector Current − Continuous, max: 0.3 A
• Collector Dissipation: 8 W
• DC Current Gain (h_fe): 100 to 200
• Transition Frequency, min: 600 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-126F

Here is an image showing the pin diagram of this transistor.The 2SC3951-E transistor can have a current gain of 100 to 200. The gain of the 2SC3951 will be in the range from 40 to 320, for the 2SC3951-C it will be in the range from 40 to 80, for the 2SC3951-D it will be in the range from 60 to 120, for the 2SC3951-F it will be in the range from 160 to 320.Sometimes the "2S" prefix is not marked on the package - the 2SC3951-E might only be marked "C3951-E".The complementary PNP transistor to the 2SC3951-E is the 2SA1536-E.The 2SC4209 (SOT-23) is the SMD version of the 2SC3951-E transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2SC3951-E with the 2SC1212A, 2SC1212A-C, 2SC2590, 2SC2590-Q, 2SC2590-R, 2SC2690, 2SC2690-Q, 2SC2824, 2SC3421, 2SC3599, 2SC3599-E, 2SC3952, 2SC3952-E, 2SC3954, 2SC3954-E, 2SD1684, 2SD1684-Q, 2SD1724, 2SD1724-R, 2SD1725, 2SD1725-R, 2SD414, 2SD414-Q, 2SD415, 2SD415-Q, 2SD600, 2SD600-E, 2SD600K, 2SD600K-E, 2SD669, 2SD669-C, BD139, BD139-16, BD139G, BD169, BD179, BD230, BD237, BD237G, BD379, BD379-16, BD789, BD791, BDX37, KSC2690, KSC2690-O, KSE182, KTC2803, KTC2803-Y, MJE182, MJE182G, MJE240, MJE242, MJE244 or MJE722.