2N4123 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 30 V
• Collector-Base Voltage, max: 40 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 0.2 A
• Collector Dissipation: 0.625 W
• DC Current Gain (h_fe): 50 to 200
• Transition Frequency, min: 250 MHz
• Noise Figure, max: 6 dB
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92
• Electrically Similar to the Popular MPS4123 transistor

The 2N4123 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, base, and collector leads.
Here is an image showing the pin diagram of this transistor.The MPS4123 is the TO-92 version of the 2N4123.You can replace the 2N4123 with the 2SC1008, 2SC815, BC537, KSC1008, KSC815, KSP05, MPS6532, MPS6602 or MPS6602G.