BCX51 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -45 V
• Collector-Base Voltage, max: -45 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -1 A
• Collector Dissipation: 1.2 W
• DC Current Gain (h_fe): 63 to 250
• Transition Frequency, min: 50 MHz
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: SOT-89

Here is an image showing the pin diagram of this transistor.The BCX51 transistor can have a current gain of 63 to 250. The gain of the BCX51-10 will be in the range from 63 to 150, for the BCX51-16 it will be in the range from 100 to 250.The BCX51 transistor is marked as "AA".The complementary NPN transistor to the BCX51 is the BCX54.You can replace the BCX51 with the 2SA1364, BCX52 or BCX53.