BUY MMBT5550 https://www.utsource.net/itm/p/11274813.html
MMBT5550 NPN 160V 0.6A HEF=60~250 SOT23 MARKING 1F
Description: NPN Bipolar Transistor Features: Low Collector-Emitter Saturation Voltage Low Noise High Gain Bandwidth Product High Current Gain High Switching Speed High Reliability Low Collector-Base Capacitance High DC Current Gain Low Collector-Emitter Leakage Current High DC Current Gain Low Collector-Base Leakage Current High DC Current Gain Low Input Capacitance High DC Current Gain Low Input Impedance Applications: Audio Amplifiers Switching Applications High Speed Switching High Frequency Amplifiers High Voltage Switching High Frequency Switching Low Noise Amplifiers High Voltage Amplifiers High Speed Amplifiers Low Frequency Amplifiers (For reference only)