BD127 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 250 V
• Collector-Base Voltage, max: 300 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 0.5 A
• Collector Dissipation: 17.5 W
• DC Current Gain (h_fe): 30
• 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 KST42 (SOT-23), MMBTA42 (SOT-23) and PZTA42 (SOT-223) is the SMD version of the BD127 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the BD127 with the 2N5655, 2N5655G, 2N5656, 2N5656G, 2N5657, 2N5657G, 2SC2752K, 2SC2752L, BD128, BD129, BD157, BD158, BD159, BD410, BUX86, BUX87, KSC2752O, KSC2752Y, KSE340, KSE5020-Y, MJE340 or MJE340G.