2N335

Introduction to Microchip Technology 2N335

The Microchip Technology 2N335 is a high-voltage, high-current NPN power transistor designed for general-purpose switching and amplification applications. It belongs to the family of bipolar junction transistors (BJTs) and is typically used in power control circuits, audio amplification, and other applications that require reliable and efficient switching. This transistor offers a balance of power handling capability, frequency performance, and thermal stability, making it suitable for a wide variety of electronic designs.

Key Specifications

* Type: NPN Bipolar Junction Transistor (BJT)
The 2N335 is an NPN type transistor, meaning it has a layer of P-type semiconductor material sandwiched between two N-type materials. This structure makes it suitable for switching and amplification tasks in both low- and high-power applications.

* Collector-Emitter Voltage (Vceo): 80V
The 2N335 can handle a maximum voltage of 80V between the collector and emitter. This makes it suitable for use in medium-voltage circuits, where voltages higher than 20V but lower than 100V are common.

* Collector Current (Ic): 15A
The maximum collector current of 15A is a critical specification for power applications. The 2N335 can handle high currents, making it ideal for driving motors, switching high-power loads, or serving as the main switching element in power supplies.

* Power Dissipation (Ptot): 90W
The maximum power dissipation rating of 90W indicates the transistor's ability to handle the energy that is lost as heat during operation. It can be used in applications where substantial power dissipation is expected without risk of overheating or damage.

* DC Current Gain (hFE): 20 to 150
The DC current gain, also known as the current transfer ratio (hFE), represents the efficiency with which the transistor can amplify current. In the case of the 2N335, the hFE varies between 20 and 150, depending on the operating conditions, meaning it provides significant amplification for signal applications.

* Base-Emitter Voltage (Vbe): 1.2V (typical)
The base-emitter voltage is the voltage required to forward bias the transistor. For the 2N335, this value is typically 1.2V, meaning that applying this voltage between the base and emitter will enable current flow from the collector to the emitter.

* Frequency Response (fT): 20 MHz (typical)
The transition frequency, or fT, is the frequency at which the transistor's current gain drops to 1. For the 2N335, the typical fT is around 20 MHz. This indicates the frequency at which it can effectively amplify signals. While this is not a high-frequency transistor, it is suitable for many low- and medium-frequency applications.

* Package Type: TO-3
The 2N335 is available in a TO-3 package, a metal can with three leads for connection. This package provides excellent heat dissipation and is commonly used for power transistors due to its ability to handle high current and power dissipation.

* Thermal Resistance (Junction to Case): 1.6°C/W
Thermal resistance indicates how efficiently the transistor can dissipate heat. For the 2N335, the junction-to-case thermal resistance is 1.6°C/W, which means for every watt of power dissipated, the junction temperature increases by 1.6°C. This helps determine the cooling requirements for the transistor in various applications.

Functional Features

* Switching Applications: The 2N335 is commonly used in switching applications, where it can act as a high-power switch to control current flow in power supplies, motor controllers, and other high-power circuits. Its high current rating makes it ideal for power-hungry applications.

* Amplification: As an amplifier, the 2N335 is often used in audio circuits, where it can amplify low-level signals to higher power levels. Its current gain, along with its relatively low base-emitter voltage, allows it to function efficiently in linear amplification applications.

* Thermal Stability: The transistor's ability to dissipate 90W of power without overheating ensures it can be used in environments where thermal management is a concern. The TO-3 package is particularly effective in transferring heat away from the transistor, ensuring reliable operation over a wide range of temperatures.

* Low Saturation Voltage: The 2N335 has a relatively low saturation voltage, which means it can switch on and off with minimal voltage drop across the collector-emitter junction. This characteristic helps to minimize power loss during switching operations, improving the overall efficiency of power circuits.

Applications

* Audio Amplifiers: The 2N335 is commonly used in audio amplification circuits, particularly in high-power audio amplifiers for home theater systems, public address systems, and professional sound equipment. Its ability to handle significant current and power dissipation makes it ideal for driving speakers.

* Motor Control: In motor control applications, the 2N335 can be used to switch large currents to motors, enabling precise control over motor speed and direction. Its high current rating makes it ideal for driving both AC and DC motors in industrial machinery.

* Power Supplies: The transistor is widely used in power supply circuits, particularly in the switching sections of power supplies where it acts as a switch to convert AC to DC or regulate voltage. Its high current and voltage ratings ensure stable operation in demanding power conversion applications.

* Switching Circuits: Due to its robust switching capabilities, the 2N335 is used in a variety of general-purpose switching applications. This includes load switching, light dimmers, and relay drivers, where it can efficiently control the current flow to connected devices.

* Regulators and Amplifiers: The 2N335 is also used in voltage regulation and audio amplification circuits, where it can function as a linear regulator or as part of an active feedback loop. Its stable gain and low base-emitter voltage ensure consistent performance in these circuits.

Reliability and Durability

The 2N335, being a high-power transistor, is built for reliability in demanding environments. The TO-3 metal package provides excellent heat dissipation and mechanical robustness, making it suitable for harsh industrial environments. Additionally, the transistor's ability to withstand high currents and voltages, combined with its thermal stability, makes it ideal for long-lasting use in power electronics.

Conclusion

The Microchip Technology 2N335 is a versatile and reliable high-power NPN transistor that finds applications in a variety of fields, including audio amplification, motor control, power supplies, and general-purpose switching circuits. With its robust specifications, including a 15A collector current rating, 80V collector-emitter voltage, and 90W power dissipation, it is well-suited for demanding power applications. Its thermal stability, efficient switching performance, and ability to handle high currents make it a valuable component in both consumer and industrial electronics.