2SC3951-D 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): 60 to 120
• 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-D transistor can have a current gain of 60 to 120. 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-E it will be in the range from 100 to 200, 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-D might only be marked "C3951-D".The complementary PNP transistor to the 2SC3951-D is the 2SA1536-D.You can replace the 2SC3951-D with the 2N4923, 2N4923G, 2SC1212A, 2SC1212A-B, 2SC2690, 2SC2690-R, 2SC3599, 2SC3599-D, 2SC3952, 2SC3952-D, 2SC3954, 2SC3954-D, 2SD414, 2SD414-R, 2SD415, 2SD415-R, 2SD600, 2SD600-D, 2SD600K, 2SD600K-D, 2SD669, 2SD669-B, BD139, BD139G, BD169, BD179, BD230, BD237, BD237G, BD379, BD441, BD441G, BD789, BD791, BDX37, KSC2690, KSC2690-R, KSE182, MJE182, MJE182G, MJE240, MJE241, MJE242, MJE243, MJE243G, MJE244 or MJE722.