2N4403 Transistor Datasheet, Pinout & Applications


Transistors are the backbone of modern electronics, serving as essential building blocks in countless electronic circuits. One such versatile transistor is the 2N4403. In this comprehensive guide, we will explore the 2N4403 transistor in detail, providing valuable insights into its datasheet, pinout, and features. Whether you are a professional engineer or an electronics enthusiast, understanding the capabilities and specifications of the 2N4403 transistor can greatly enhance your design and troubleshooting skills.

Table of Contents:

  • What is a Transistor?
  • Understanding the 2N4403 Transistor
  • 2N4403 Transistor Datasheet
  • 2N4403 Transistor Pinout
  • Features of the 2N4403 Transistor
  • Frequently Asked Questions (FAQs)
  • Conclusion

What is a Transistor?

A transistor is a three-terminal semiconductor device that amplifies or switches electronic signals and electrical power. It acts as a current amplifier or a switch, regulating the flow of electric current within a circuit. Transistors have revolutionized the field of electronics, leading to the development of smaller, more efficient, and powerful electronic devices.

Understanding the 2N4403 Transistor:

The 2N4403 is a general-purpose, small-signal NPN transistor commonly used in low-power amplification and switching applications. It belongs to a class of transistors known as bipolar junction transistors (BJTs), which consist of three layers of semiconductor material. The 2N4403 transistor is specifically designed for applications that require high gain and low noise.

2N4403 Transistor Datasheet:

A datasheet provides detailed technical specifications and performance characteristics of a component. Let’s look at the key specifications included in the datasheet of the 2N4403 transistor:

  • Maximum Collector-Emitter Voltage (VCEO): This specification represents the maximum voltage that can be applied between the collector and emitter terminals of the transistor.
  • Maximum Collector Current (IC): It refers to the maximum current that can flow through the collector terminal.
  • Maximum Power Dissipation (Pd): This specification indicates the maximum power that the transistor can handle without getting damaged.
  • DC Current Gain (hFE): It defines the ratio of collector current to the base current and provides information about the amplification capability of the transistor.
  • Transition Frequency (fT): This parameter determines the maximum frequency at which the transistor can operate effectively.
  • Collector-Emitter Saturation Voltage (VCE(sat)): It represents the voltage drop between the collector and emitter when the transistor is fully turned on.

The datasheet also provides information about the package type, pin configuration, and recommended operating conditions.

Sure! Here’s the datasheet and pinout information for the 2N4403 transistor presented in a table format:

Transistor Model2N4403
Maximum Voltage40V
Maximum Current600mA
Power Dissipation625mW
Package TypeTO-92

2N4403 Transistor Pinout:

Understanding the pinout of a transistor is crucial for proper circuit integration. The 2N4403 transistor typically comes in a TO-92 package, which consists of three leads. Here is the pinout configuration of the 2N4403 transistor:

  • Pin 1 (Emitter): The emitter terminal is responsible for controlling the flow of electrons from the emitter to the base.
  • Pin 2 (Base): The base terminal is used to control the transistor’s conductivity by regulating the current flowing through it.
  • Pin 3 (Collector): The collector terminal collects the majority of the current flowing through the transistor.

By correctly identifying and connecting the pins of the 2N4403 transistor, you can ensure its optimal performance within your circuit.

Pinout Configuration:

Pin NumberDescription

Please note that the pinout configuration may vary depending on the manufacturer, so it’s always a good idea to refer to the datasheet provided by the manufacturer for accurate information.

Features of the 2N4403 Transistor:

The 2N4403 transistor offers several features that make it a popular choice among designers and hobbyists. Let’s explore some of its key features:

  • High Gain: With a high DC current gain (hFE) of typically 100 to 300, the 2N4403 transistor provides significant amplification capabilities, making it suitable for low-power audio and general-purpose amplification applications.
  • Low Noise: The 2N4403 transistor is designed to minimize noise interference, making it ideal for applications where signal clarity is crucial.
  • Low Saturation Voltage: The collector-emitter saturation voltage (VCE(sat)) of the 2N4403 transistor is relatively low, enabling efficient switching operations.
  • Wide Operating Temperature Range: The 2N4403 transistor can withstand a wide range of temperatures, typically from -65°C to +150°C, making it suitable for use in various environments.
  • Cost-Effective: The 2N4403 transistor is readily available and affordable, making it a cost-effective choice for many applications.


The 2N4403 transistor is a versatile component widely used in various electronic circuits. In this comprehensive guide, we explored its datasheet, pinout, and features, providing valuable insights for professionals and enthusiasts. Understanding the capabilities and specifications of the 2N4403 transistor enables designers to optimize their circuits, ensuring reliable performance and efficient operation. Whether you are a seasoned engineer or an electronics hobbyist, the 2N4403 transistor is a valuable tool in your arsenal, offering high gain, low noise, and cost-effective solutions for your electronic projects.

6. Frequently Asked Questions (FAQs):

Q1: What are the typical applications of the 2N4403 transistor?

The 2N4403 transistor finds applications in various electronic circuits, including:

  • Audio amplifiers
  • Switching circuits
  • Oscillators
  • Voltage regulators
  • Signal processing circuits

Q2: Can the 2N4403 transistor handle high power applications?

No, the 2N4403 transistor is designed for low-power applications. For high-power applications, power transistors with higher current and voltage ratings should be used.

Q3: How can I determine the authenticity of a 2N4403 transistor?

To ensure authenticity, purchase transistors from reliable suppliers or authorized distributors. Check for proper packaging, original markings, and compare the specifications with the datasheet.

Q4: Can the 2N4403 transistor be used in automotive applications?

Yes, the 2N4403 transistor can be used in automotive applications, provided it meets the required specifications and standards.

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