2N3439 / 2N3440 Silicon Epitaxial Planar NPN Transistor

Overview

The 2N3439 and 2N3440 are silicon epitaxial planar NPN transistors housed in a JEDEC TO-39 metal case package. These transistors are designed for general-purpose amplification and switching applications, offering robust performance in a wide range of operating conditions. The epitaxial planar construction ensures high reliability, low noise, and excellent thermal stability, making them suitable for both commercial and industrial applications.

These devices are characterized by their medium power handling capability, good frequency response, and high current gain. The TO-39 package provides effective heat dissipation and mechanical durability, which is essential for applications requiring long-term reliability.

Features

• High Current Gain (h_FE): Typical values ranging from 40 to 120, ensuring efficient signal amplification.
• Medium Power Handling: Maximum collector power dissipation of 1.0W (at 25°C), suitable for a variety of amplification and switching tasks.
• Low Saturation Voltage: Ensures minimal power loss in switching applications.
• Excellent Frequency Response: Transition frequency (f_T) up to 50MHz, making it suitable for RF and audio applications.
• Robust Construction: Epitaxial planar process enhances reliability and thermal performance.
• TO-39 Metal Package: Provides superior heat dissipation and mechanical strength.
• Wide Operating Temperature Range: -65°C to +200°C, ensuring performance in extreme environments.

Applications

The 2N3439 and 2N3440 transistors are versatile components used in a broad spectrum of electronic circuits. Their key applications include:

• General-Purpose Amplification: Used in audio amplifiers, signal processing circuits, and small-signal amplification stages.
• Switching Circuits: Suitable for relay drivers, motor control, and power switching due to their low saturation voltage.
• RF Applications: Employed in radio frequency amplifiers and oscillators owing to their good frequency response.
• Industrial Control Systems: Used in automation and control circuits where reliability is critical.
• Consumer Electronics: Found in televisions, radios, and other household electronic devices.
• Military and Aerospace: Their wide temperature range and rugged construction make them suitable for harsh environments.

Electrical Characteristics

The following tables outline the key electrical specifications for the 2N3439 and 2N3440 transistors under standard test conditions (unless otherwise noted).

Absolute Maximum Ratings

• Collector-Base Voltage (V_CB): 60V (2N3439), 80V (2N3440)
• Collector-Emitter Voltage (V_CE): 40V (2N3439), 60V (2N3440)
• Emitter-Base Voltage (V_EB): 6V
• Collector Current (I_C): 1A (continuous)
• Total Power Dissipation (P_D): 1.0W at 25°C (derate linearly above 25°C)
• Operating and Storage Temperature Range: -65°C to +200°C

Typical Electrical Characteristics (T_A = 25°C)

• DC Current Gain (h_FE): 40 to 120 (at I_C = 10mA, V_CE = 1V)
• Collector-Emitter Saturation Voltage (V_CE(sat)): ≤ 0.3V (at I_C = 500mA, I_B = 50mA)
• Base-Emitter Saturation Voltage (V_BE(sat)): ≤ 1.2V (at I_C = 500mA, I_B = 50mA)
• Transition Frequency (f_T): 50MHz (typical, at I_C = 10mA, V_CE = 20V)
• Collector-Base Breakdown Voltage (BV_CEO): ≥ 60V (2N3439), ≥ 80V (2N3440)
• Collector-Emitter Breakdown Voltage (BV_CEO): ≥ 40V (2N3439), ≥ 60V (2N3440)
• Emitter-Base Breakdown Voltage (BV_EBO): ≥ 6V

Package Information

The 2N3439 and 2N3440 transistors are housed in a JEDEC TO-39 metal can package. This package is widely recognized for its durability, thermal performance, and ease of mounting in both through-hole and heatsink applications.

TO-39 Package Dimensions

• Case Material: Metal (typically steel or alloy)
• Lead Material: Tinned copper or alloy
• Diameter: 8.13mm (0.320 inches) max
• Height: 6.35mm (0.250 inches) max
• Lead Spacing: 5.08mm (0.200 inches) between leads
• Weight: Approximately 1.2 grams

Mounting Considerations

The TO-39 package is designed for through-hole mounting on printed circuit boards (PCBs). For high-power applications, it is recommended to use a heatsink to maintain optimal thermal performance. The metal case can be electrically isolated if necessary, but care must be taken to avoid short circuits with adjacent components.

Pin Configuration

• Pin 1: Emitter (E)
• Pin 2: Base (B)
• Pin 3: Collector (C) – connected to the metal case

Thermal Characteristics

Proper thermal management is critical to ensure the longevity and reliability of the transistor. The following thermal parameters are specified:

• Thermal Resistance, Junction-to-Ambient (R_θJA): 200°C/W (typical without heatsink)
• Thermal Resistance, Junction-to-Case (R_θJC): 83.3°C/W
• Maximum Junction Temperature (T_J): 200°C

Reliability and Quality

The 2N3439 and 2N3440 transistors are manufactured using stringent quality control processes to ensure high reliability. These devices are typically rated for industrial and military applications, with some variants meeting MIL-STD-883 standards for ruggedness and performance under extreme conditions.

Conclusion

The 2N3439 and 2N3440 NPN transistors are versatile, high-performance components suitable for a wide range of amplification and switching applications. Their robust TO-39 metal package, excellent electrical characteristics, and broad operating temperature range make them ideal for both commercial and industrial use. Engineers and designers can rely on these transistors for reliable operation in demanding environments.