BC259 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -20 V
• Collector-Base Voltage, max: -25 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -0.1 A
• Collector Dissipation: 0.3 W
• DC Current Gain (h_fe): 110 to 800
• Transition Frequency, min: 180 MHz
• Noise Figure, max: 1.2 dB
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92

The BC259 is manufactured in a plastic TO-92 case. When looking at the flat side with the leads pointed downward, the three leads emerging from the transistor are, from left to right, the emitter, collector, and base leads.
Here is an image showing the pin diagram of this transistor.The BC259 transistor can have a current gain of 110 to 800. The gain of the BC259A will be in the range from 110 to 220, for the BC259B it will be in the range from 200 to 450, for the BC259C it will be in the range from 420 to 800.The complementary NPN transistor to the BC259 is the BC169.You can replace the BC259 with the 2SA628, BC258, MPS3638, MPS3638A, PN3638 or PN3638A.