BSR40 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 60 V
• Collector-Base Voltage, max: 70 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 1 A
• Collector Dissipation: 1.35 W
• DC Current Gain (h_fe): 40 to 120
• Transition Frequency, min: 100 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 BSR40 transistor is marked as "AR1".The complementary PNP transistor to the BSR40 is the BSR30.You can replace the BSR40 with the BSR42.