BCX20 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: 0.8 A
• Collector Dissipation: 0.31 W
• DC Current Gain (h_fe): 100 to 600
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: SOT-23

Here is an image showing the pin diagram of this transistor.The BCX20 transistor is marked as "U2".You can replace the BCX20 with the BCW65, BCW66 or FMMT619.