MJE340 NPN Power Transistor Datasheet

Introduction

The MJE340 is a high-voltage NPN power transistor designed for use in switching power supplies, amplifiers, and high-voltage driver applications. Packaged in a TO-225 case, it offers excellent thermal dissipation and mechanical strength for medium-power electronic circuits. Because of its high collector-emitter voltage rating and stable gain, the MJE340 is commonly used in audio amplifier circuits, CRT drivers, and high-voltage regulator stages.

One of the major advantages of the MJE340 transistor is its ability to handle collector-emitter voltages up to 300V and a continuous collector current of 0.5A. This makes it suitable for circuits where both voltage endurance and moderate current handling are required. The transistor also has good switching characteristics, which makes it a reliable choice in high-frequency driver circuits and power management applications.

MJE340 NPN Power Transistor

The MJE340 NPN transistor is also widely available and cost-effective, making it a popular choice among hobbyists, circuit designers, and industrial applications alike. Its complementary PNP counterpart is the MJE350, and together they are frequently used in push-pull amplifier stages and other symmetrical designs.

MJE340 Pinout

Pin Configuration

Key Features

• High collector-emitter voltage rating (up to 300V).
• Suitable for audio, switching, and regulator circuits.
• TO-225 package ensures durability and better heat dissipation.
• Moderate collector current handling (500mA).
• Reliable performance in medium-power applications.

Characteristics

• Transistor Type: NPN
• Collector-Emitter Voltage (Vce): 300V
• Collector-Base Voltage (Vcb): 300V
• Emitter-Base Voltage (Veb): 5V
• Collector Current (Ic): 0.5A
• Power Dissipation (Pd): 20W (with proper heatsink)
• DC Current Gain (hFE): 40 – 240
• Transition Frequency (ft): 50 MHz (typical)
• Package Type: TO-225

More Circuit Layouts

Key Applications of MJE340 NPN Power Transistor

• Audio amplifier driver stages.
• High-voltage switching circuits.
• Regulated power supply circuits.
• CRT monitor and TV driver circuits.
• General purpose medium-power switching.

PNP Complimentary Transistor

MJE350 (PNP Power Transistor, TO-225).

Equivalent of MJE340 NPN Power Transistor

• 2N5551 (for low-power designs).
• BF422, BF423 (similar high-voltage transistors).
• KSP44, KSP92 (NPN alternatives with high voltage tolerance).
• BD139 (for lower voltage but higher current needs).

(Pin configuration of some transistors mentioned above may different from MJE340).

Datasheet of MJE1340 NPN Power Transistor

Click the following Button to download the datasheet of MJE340 Transistor :

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