2N3391A Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 25 V
• Collector-Base Voltage, max: 25 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 0.5 A
• Collector Dissipation: 0.625 W
• DC Current Gain (h_fe): 250 to 500
• Noise Figure, max: 5 dB
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92

The 2N3391A is manufactured in a plastic TO-92 case. When looking at the flat side with the leads pointed downward, the three leads emerging from the transistor are, from left to right, the emitter, collector, and base leads.
Here is an image showing the pin diagram of this transistor.The BC818 (SOT-23), BC818-40 (SOT-23), BC818-40W (SOT-323) and BC818W (SOT-323) is the SMD version of the 2N3391A transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2N3391A with the 2N3391, 2N3394, 2N3415, 2N3417, 2SC2500, 2SC2500-A, 2SC2500-B, 2SC2500-C, 2SC2500-D, 2SC3916, 2SC3917, 2SC3918, 2SC3919, 2SC3920, 2SC3921, 2SC3922, 2SC3923, 2SD1207, 2SD1347, 2SD1616, 2SD1835, 2SD545, 2SD789, 2SD789-D, KSC2500, KSC2500-A, KSC2500-B, KSC2500-C, KSC2500-D, KSC5019, KSD1616 or NTE192A.