ZTX550 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -45 V
• Collector-Base Voltage, max: -60 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -1 A
• Collector Dissipation: 1 W
• DC Current Gain (h_fe): 100 to 300
• Transition Frequency, min: 150 MHz
• Operating and Storage Junction Temperature Range: -55 to +200 °C
• Package: TO-92

The ZTX550 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, base, and collector leads.
Here is an image showing the pin diagram of this transistor.The 2SB1122 (SOT-89), 2SB710A (SOT-23), 2SB766A (SOT-89), BCW68 (SOT-23) and MMBT200 (SOT-23) is the SMD version of the ZTX550 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the ZTX550 with the BC527, BC528, MPS4354, MPS4355, MPS751, MPS751G or ZTX951.