2N4125 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -30 V
• Collector-Base Voltage, max: -30 V
• Emitter-Base Voltage, max: -4 V
• Collector Current − Continuous, max: -0.2 A
• Collector Dissipation: 0.625 W
• DC Current Gain (h_fe): 50 to 150
• Transition Frequency, min: 200 MHz
• Noise Figure, max: 5 dB
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92
• Electrically Similar to the Popular MPS4125 transistor

The 2N4125 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 MMBT4125 (SOT-23) is the SMD version of the 2N4125 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.The MPS4125 is the TO-92 version of the 2N4125.You can replace the 2N4125 with the 2N3905, 2N4402, 2SA539, 2SA708, BC527, KSA539, KSA708, KSP55, MPS3703, MPS4125, MPS4354, MPS6535, MPS6652, MPS6652G, MPSW55, MPSW55G, PN4354 or ZTX551.