2N4124 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 25 V
• Collector-Base Voltage, max: 30 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 0.2 A
• Collector Dissipation: 0.625 W
• DC Current Gain (h_fe): 120 to 480
• Transition Frequency, min: 300 MHz
• Noise Figure, max: 5 dB
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92
• Electrically Similar to the Popular MPS4124 transistor

The 2N4124 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 BC848 (SOT-23), BC848W (SOT-323), BC849 (SOT-23), BC849W (SOT-323), MMBT4124 (SOT-23) and MMST4124 (SOT-323) is the SMD version of the 2N4124 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.The MPS4124 is the TO-92 version of the 2N4124.You can replace the 2N4124 with the 2N5172, MPS650, MPS650G, MPS6532, MPS6601, MPS6601G, MPS6602, MPS6602G, MPSW01, MPSW01A, MPSW01AG or MPSW01G.