2N4037 Pinout, Equivalent, Application, Datasheet

The 2N4037 is a PNP silicon transistor housed in a durable TO-39 metal package, widely used in audio amplifiers, switching circuits, and signal control stages. It delivers reliable operation with a collector-emitter voltage (Vce) of –40 V and a collector-base voltage (Vcb) of –60 V, making it suitable for medium-voltage applications. The 2N4037 pinout follows the Emitter–Base–Collector (E-B-C) sequence, enabling easy installation and compatibility with standard TO-39 sockets.

This transistor provides up to –1 A of collector current and can dissipate 5 W of power, ensuring dependable thermal and electrical performance. Its low leakage current and moderate current gain make it ideal for analog signal amplification, driver stages, and low-frequency oscillators, where precision and reliability are essential.

Introduction to 2N4037 PNP Transistor

The 2N4037 is a general-purpose PNP transistor designed for use in linear and switching circuits that demand moderate power and voltage control. Constructed with silicon planar technology, it provides stable current gain and minimal distortion in amplifier configurations.

Its TO-39 metal can ensures excellent heat dissipation and long-term durability, even under continuous load conditions. Because of its balanced combination of voltage handling, current capacity, and power dissipation, the 2N4037 remains a reliable option in industrial electronics, audio circuits, and instrumentation equipment.

2N4037 PNP Transistor

Pinout of 2N4037

Pin Configuration of 2N4037 Pinout

Key Features of 2N4037 Transistor

• PNP silicon transistor for medium-power circuits
• TO-39 metal case ensures thermal efficiency
• Reliable in both switching and linear operations
• Low noise and stable current gain performance
• High durability under thermal stress
• Compatible with standard amplifier and driver designs

2N4037 Transistor Datasheet and Specifications

• Transistor Type: PNP Silicon
• Collector-Emitter Voltage (Vce): –40 V
• Collector-Base Voltage (Vcb): –60 V
• Emitter-Base Voltage (Veb): –5 V (typical)
• Collector Current (Ic): –1 A
• Power Dissipation (Ptot): 5 W
• DC Current Gain (hFE): 30 – 120
• Transition Frequency (fT): 40 MHz (typical)
• Operating Temperature Range: –65 °C to +200 °C
• Package Type: TO-39 Metal Can
• Pin Configuration: Emitter – Base – Collector (E-B-C)

Equivalent and Alternative Transistors

If the 2N4037 is not available, the following transistors can be used as alternatives:

• 2N4036 – PNP, –65 V, –1 A, TO-39
• 2N5415 – PNP, –200 V, –1 A, TO-39
• BD140 – PNP, –80 V, –1.5 A, TO-126
• MJE350 – PNP, –300 V, –0.5 A, TO-126
• 2N2907A – PNP, –60 V, –0.6 A, TO-18

These equivalents share similar characteristics and can serve as substitutes depending on circuit voltage and current requirements.

More Circuit Layouts

Applications of 2N4037 Transistor

The 2N4037 is suitable for a wide range of applications, such as:

• Audio and preamplifier circuits
• Low-frequency oscillators and waveform generators
• Voltage regulators and feedback loops
• Signal drivers and sensor interfaces
• Analog amplification stages in industrial or laboratory equipment

Its compact metal-can structure and stable operation make it a reliable choice for medium-power analog electronics.

Working Principle of 2N4037 Transistor

The 2N4037 PNP transistor conducts when its base voltage is lower than its emitter voltage. In amplifier circuits, a small base current controls a larger current between the emitter and collector, providing current amplification. When used as a switch, it alternates between cut-off (OFF) and saturation (ON) states, allowing efficient control of medium-power loads.

Advantages of 2N4037 Transistor

• Consistent current gain and low noise characteristics
• Long-term reliability in audio and signal circuits
• Compact, metal-can design with effective heat dissipation
• Suitable for both analog and digital switching
• Wide thermal operating range

Conclusion

The 2N4037 PNP transistor is a dependable and efficient medium-power device designed for amplifier and switching applications. With a –40 V collector-emitter rating, –1 A current capacity, and 5 W dissipation, it performs reliably in audio, control, and instrumentation circuits.

Its 2N4037 pinout (E-B-C) and TO-39 metal enclosure make it an excellent fit for projects that demand stability, durability, and precision in compact high-voltage designs.

Datasheet & Pinout of 2N4037 PNP Transistor

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