FMMT591Q Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -60 V
• Collector-Base Voltage, max: -80 V
• Emitter-Base Voltage, max: -7 V
• Collector Current − Continuous, max: -1 A
• Collector Dissipation: 0.5 W
• DC Current Gain (h_fe): 100 to 300
• Transition Frequency, min: 150 MHz
• 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 FMMT591Q transistor is marked as "591".The complementary NPN transistor to the FMMT591Q is the FMMT491Q.You can replace the FMMT591Q with the FMMT591.