MJE340 Silicon Epitaxial Planar NPN Transistor

Overview

The MJE340 is a high-voltage, silicon epitaxial planar NPN transistor designed for general-purpose amplifier and switching applications. This robust component is engineered to deliver reliable performance in demanding electronic circuits, offering a balance of high voltage capability, current handling, and thermal stability. Its construction utilizes epitaxial planar technology, ensuring consistent electrical characteristics and low leakage currents.

With a collector-emitter voltage rating of 300V and a collector current of 500mA, the MJE340 is suitable for a wide range of medium-power applications. The transistor is housed in a TO-126 package, providing a compact footprint while maintaining effective thermal dissipation.

Features

• High Voltage Capability: Collector-emitter voltage (V_CEO) of 300V, making it suitable for high-voltage circuits.
• Moderate Current Handling: Continuous collector current (I_C) of 500mA.
• Low Leakage Current: Ensures minimal power loss in off-state conditions.
• Epitaxial Planar Construction: Provides stable performance and low noise operation.
• TO-126 Package: Compact and thermally efficient for medium-power dissipation.
• Wide Operating Temperature Range: Typically rated from -65°C to +150°C.
• Complementary PNP Option: MJE350 is the PNP counterpart for push-pull configurations.

Applications

The MJE340 is versatile and finds use in a variety of electronic circuits, including:

• Linear Amplifiers: Used in audio and signal amplification stages due to its low distortion characteristics.
• Switching Circuits: Suitable for relay drivers, motor control, and power supply switching.
• High-Voltage Power Supplies: Employed in voltage regulation and DC-DC converter circuits.
• CRT Display Systems: Used in deflection and high-voltage drive circuits.
• Industrial Control Systems: Provides reliable switching and amplification in control modules.

Electrical Characteristics

Absolute Maximum Ratings

• Collector-Emitter Voltage (V_CEO): 300V
• Collector-Base Voltage (V_CBO): 400V
• Emitter-Base Voltage (V_EBO): 5V
• Collector Current (I_C): 500mA (continuous)
• Base Current (I_B): 100mA
• Total Power Dissipation (P_tot): 20W at 25°C (derate above 25°C)
• Operating and Storage Temperature Range: -65°C to +150°C

Typical Electrical Characteristics (at 25°C unless specified)

• DC Current Gain (h_FE): 30 to 150 at I_C = 100mA, V_CE = 10V
• Collector-Emitter Saturation Voltage (V_CE(sat)): 0.5V max at I_C = 200mA, I_B = 20mA
• Base-Emitter Saturation Voltage (V_BE(sat)): 1.2V max at I_C = 200mA, I_B = 20mA
• Transition Frequency (f_T): 10MHz typical at I_C = 50mA, V_CE = 10V
• Collector Cut-off Current (I_CEO): 100µA max at V_CE = 300V

Package Information

TO-126 Package Dimensions

• Package Type: TO-126 (also known as SOT-32)
• Mounting Style: Through-hole
• Weight: Approximately 0.8 grams
• Pin Configuration:
  • Pin 1: Emitter
  • Pin 2: Base
  • Pin 3: Collector
• Thermal Resistance (Junction-to-Ambient): 62.5°C/W (without heatsink)

Mechanical Drawing

The TO-126 package features a compact, molded plastic body with a metal tab for optional heatsink attachment. The leads are made of tinned copper for reliable solderability. Detailed mechanical drawings, including exact dimensions and tolerances, are available in the manufacturer's datasheet.

Reliability and Compliance

The MJE340 is manufactured under strict quality control standards to ensure long-term reliability. It complies with industry-standard environmental and safety regulations, including RoHS (Restriction of Hazardous Substances) directives. For mission-critical applications, it is recommended to consult the manufacturer's reliability reports and qualification data.

Conclusion

The MJE340 is a dependable NPN transistor that excels in high-voltage and medium-power applications. Its combination of electrical robustness, thermal performance, and versatility makes it a preferred choice for designers working on amplifiers, switching circuits, and power management systems. With its TO-126 package and complementary PNP counterpart (MJE350), it offers flexibility in circuit design while maintaining cost-effectiveness.