BD138 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -60 V
• Collector-Base Voltage, max: -60 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -1.5 A
• Collector Dissipation: 12.5 W
• DC Current Gain (h_fe): 40 to 250
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-126

Here is an image showing the pin diagram of this transistor.The BD138 transistor can have a current gain of 40 to 250. The gain of the BD138-10 will be in the range from 63 to 160, for the BD138-16 it will be in the range from 100 to 250, for the BD138-6 it will be in the range from 40 to 100.The complementary NPN transistor to the BD138 is the BD137.The BCP52 (SOT-223) is the SMD version of the BD138 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the BD138 with the BD138G, BD140, BD140G, BD168, BD170, BD178, BD180, BD180G, BD190, BD229, BD231, BD236, BD236G, BD238, BD238G, BD378, BD380, BD788, BD788G, BD790, BD792, MJE235, MJE252, MJE254, MJE711 or MJE712.The BD138G transistor is the lead-free version of the BD138.