BD137 Bipolar Transistor

• Type: NPN
• 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 BD137 transistor can have a current gain of 40 to 250. The gain of the BD137-10 will be in the range from 63 to 160, for the BD137-16 it will be in the range from 100 to 250, for the BD137-6 it will be in the range from 40 to 100.The complementary PNP transistor to the BD137 is the BD138.The BCP55 (SOT-223) is the SMD version of the BD137 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the BD137 with the BD137G, BD139, BD139G, BD167, BD169, BD177, BD179, BD189, BD228, BD230, BD235, BD235G, BD237, BD237G, BD377, BD379, BD787, BD787G, BD789, BD791, MJE225, MJE242, MJE244, MJE721 or MJE722.The BD137G transistor is the lead-free version of the BD137.