2N3421

Due to market price fluctuations, if you need to purchase or consult the price. You can contact us or emial to us:   sales@allicdata.com

2N3421 is a silicon NPN transistor, one type of bipolar junction transistor (BJT). When used in an amplification circuit, the 2N3421 can drive from a few to several hundred milliwatts of power into a load. It can also be utilized as a switch or a signal modulator.

Properties and Characteristics

The 2N3421 is a general-purpose transistor, with a maximum voltage rating of 75 volts and a maximum power dissipation of 500 milliwatts. It is also capable of a maximum collector current of 250mA, maximum gain (hFE) of 200 and a maximum collector-emitter voltage (Vce(max)) of 75V. It has a typical ft (transition frequency) of 100MHz, making it quite well-suited for applications where high speeds are required. Its datasheet recommends that it should have a minimum base voltage of 3V, and it can easily handle up to 40V of collector-emitter voltage (Vce) when used in an enhancement mode.

Applications

The 2N3421 can be used in a variety of applications, including:

• Small-signal amplification: The 2N3421 is often used in audio circuits for voltage amplification (voltage gains) and for signal modulation.
• Switch: The transistor can also be used in switch applications, where it is turned on or off depending on its input signal.
• Power Amplification: The 2N3421 can be used for power amplification in audio and RF amplifiers, power supply circuits, and other medium-power applications.

Working Principle

The 2N3421 has three layers, an emitter, base, and collector. A voltage source is applied to the emitter and the base, creating a current path between them. This current flow, known as the base current, allows electrons to flow from the emitter to the collector. The electrons travel through the base and, as a result, a voltage drop is created between the base and the collector. This voltage drop is known as the collector-emitter voltage (Vce) and is utilized in amplification. As the base current increases, the collector current also increases, creating a greater voltage drop and a greater power gain.

The gain of the transistor is dependent on the amount of base current and the ratio of the base current to the collector current. This ratio is known as the current gain or hFE (hFE = Ic/Ib). This current gain can be utilized to obtain higher signal levels in amplifier circuits and can also be used to control larger currents in switch mode applications.

The 2N3421 can also be utilized in a “direct-drive” configuration, where the output of the transistor is utilized to drive a speaker directly. In this configuration, the base current is used to control the volume, while the collector current amplifies the signal.

Conclusion

The 2N3421 is a versatile bipolar junction transistor (BJT) which can be used for a variety of applications, from signal amplification to switch modulators. It has a wide voltage rating, a large current gain (hFE), and can easily handle up to 40V when used in an enhancement mode. Its ft (transition frequency) of 100MHz makes it well-suited for high-speed applications, and its datasheet recommends that it should have a minimum base voltage of 3V. The 2N3421 is a reliable, effective, diverse transistor that can be utilized in many applications.

The specific data is subject to PDF, and the above content is for reference