2N5550 NPN High-Voltage Transistor Technical Summary

Overview

The 2N5550 is a high-voltage NPN bipolar junction transistor (BJT) designed for general-purpose amplification and switching applications. Housed in a TO-92 (SOT54) plastic package, this transistor is widely used in circuits requiring high-voltage handling capabilities while maintaining low current operation. Its robust construction and reliable performance make it a popular choice among engineers and hobbyists alike.

With a maximum collector-emitter voltage (V_CEO) of 160V and a collector current (I_C) rating of 300mA, the 2N5550 is well-suited for applications demanding high-voltage amplification or switching. The device exhibits good linearity and gain characteristics, making it ideal for use in audio amplifiers, signal processing circuits, and voltage regulation systems.

Features

• High Voltage Capability: Maximum collector-emitter voltage (V_CEO) of 160V.
• Low Current Operation: Maximum collector current (I_C) of 300mA.
• High Current Gain: Typical DC current gain (h_FE) of 60 to 240, ensuring efficient signal amplification.
• Low Noise: Suitable for audio and signal processing applications where noise performance is critical.
• Compact Package: TO-92 (SOT54) plastic package for easy PCB mounting and space-saving designs.
• Wide Operating Temperature Range: Can operate in environments ranging from -55°C to +150°C.

Applications

The 2N5550 is versatile and finds use in a variety of electronic circuits, including but not limited to:

• High-Voltage Amplification: Used in audio amplifiers, RF stages, and other signal amplification circuits requiring high-voltage handling.
• Switching Circuits: Suitable for relay drivers, LED drivers, and other switching applications where moderate current and high voltage are required.
• Voltage Regulation: Employed in linear voltage regulators and power supply circuits to control and stabilize output voltages.
• Signal Processing: Used in oscillators, modulators, and other analog signal processing stages due to its low noise characteristics.
• Industrial and Consumer Electronics: Commonly found in power management circuits, inverters, and control systems.

Electrical Characteristics

The following table summarizes the key electrical characteristics of the 2N5550 transistor under standard test conditions (unless otherwise specified):

Absolute Maximum Ratings

• Collector-Emitter Voltage (V_CEO): 160V
• Collector-Base Voltage (V_CBO): 180V
• Emitter-Base Voltage (V_EBO): 6V
• Collector Current (I_C): 300mA (continuous)
• Total Power Dissipation (P_tot): 625mW at 25°C (derate above 25°C)
• Operating and Storage Temperature Range: -55°C to +150°C

DC Current Gain (h_FE)

• Minimum h_FE: 60 (at I_C = 10mA, V_CE = 5V)
• Typical h_FE: 100 (at I_C = 10mA, V_CE = 5V)
• Maximum h_FE: 240 (at I_C = 10mA, V_CE = 5V)

Small-Signal Characteristics

• Transition Frequency (f_T): 100MHz (typical at I_C = 10mA, V_CE = 20V)
• Output Capacitance (C_ob): 4pF (typical at V_CB = 10V, I_E = 0)
• Input Impedance (h_ie): 5kΩ (typical at I_C = 1mA, V_CE = 10V)

Package Information

The 2N5550 is available in a TO-92 (SOT54) plastic package, which is a through-hole mounting style widely used in low-power applications. The package dimensions and pin configuration are as follows:

TO-92 Package Dimensions

• Body Length: 4.58mm (max)
• Body Width: 3.81mm (max)
• Body Height: 4.7mm (max)
• Lead Diameter: 0.46mm (nominal)
• Lead Spacing: 2.54mm (between leads)

Pin Configuration

• Pin 1 (Emitter): Connected to the emitter region of the transistor.
• Pin 2 (Base): Connected to the base region, which controls the transistor's operation.
• Pin 3 (Collector): Connected to the collector region, which handles the main current flow.

Thermal Characteristics

Proper thermal management is essential for ensuring the longevity and reliability of the 2N5550 transistor. The following thermal characteristics should be considered during circuit design:

• Thermal Resistance, Junction-to-Ambient (R_θJA): 200°C/W (typical for TO-92 package)
• Thermal Resistance, Junction-to-Case (R_θJC): 83.3°C/W (typical)
• Maximum Junction Temperature (T_J): 150°C

Reliability and Quality

The 2N5550 is manufactured using high-quality materials and processes to ensure consistent performance and reliability. It undergoes rigorous testing to meet industry standards for electrical and thermal performance. The device is also RoHS compliant, making it suitable for use in environmentally conscious designs.

Conclusion

The 2N5550 NPN high-voltage transistor is a versatile and reliable component for a wide range of electronic applications. Its high-voltage capability, low current operation, and compact TO-92 package make it an excellent choice for amplification, switching, and voltage regulation tasks. Engineers and designers can rely on the 2N5550 for robust performance in demanding circuits.