D718 8A 120V 80W NPN High-Speed Switching Transistor TO-3P

D718 (2SD718) is a rugged and high-performance NPN power transistor designed for demanding high-current and high-power switching applications. It is widely used by engineers and technicians for driving substantial loads, including power amplifiers and switching power supplies. Encased in a durable TO-3P plastic package, the D718 offers a continuous collector current of 8A and can dissipate up to 80W when properly mounted to a heat sink. With its high voltage tolerance, fast switching characteristics, and robust build, it’s an ideal choice for professional and hobby-grade power electronics designs.

Key Features:

• High Collector Current: Supports up to 8A continuous current — ideal for driving motors, relays, and power amplifiers.
• High Power Dissipation: Handles up to 80W (at T_C = 25°C) with proper cooling.
• High Voltage Rating: Offers a Collector–Base Voltage (V_CBO) of 120V, making it suitable for higher-voltage applications.
• NPN Polarity: Standard NPN junction configuration for easy integration into existing circuit designs.
• High-Speed Switching: Performs reliably in switching regulators, inverters, and power control circuits.

Technical Specifications:

• Type: NPN Power Transistor
• Collector–Base Voltage (V_CBO): 120 V
• Collector–Emitter Voltage (V_CEO): 120 V
• Emitter–Base Voltage (V_EBO): 5 V
• Collector Current (I_C): 8 A (DC)
• Base Current (I_B): 0.8 A
• Power Dissipation (P_D): 80 W (at T_C = 25°C)
• DC Current Gain (h_FE): Typically 50–160

Mechanical Specifications:

• Package Type: TO-3P (also known as TO-247) Plastic Package
• Mounting Style: Screw-mounted via central hole to a heat sink
• Lead Configuration: Three metal leads — Base (B), Collector (C), and Emitter (E)
• Body Material: Plastic molded casing with metal base for superior heat transfer

Dimensions:

• Total Length (with leads): Approx. 40 mm
• Body Height: Approx. 20 mm
• Body Width: Approx. 16 mm
• Mounting Hole Diameter: Approx. 3.2 mm

Pinout and Wiring:

• Pin 1 (Left): Base (B) — controls current flow from Collector to Emitter.
• Pin 2 (Center): Collector (C) — main current path, typically connected to the load or power source.
• Pin 3 (Right): Emitter (E) — commonly connected to ground (GND).
• Wiring Note: The metal back tab is internally connected to the Collector (C). Use insulating washers or bushings when mounting multiple transistors to a grounded heat sink.

Datasheet Reference:

• Download D718 Datasheet (Jiangsu JSC)

Commonly Used In:

• Audio Power Amplifiers: Serves as the main output stage transistor in high-power amplifier circuits.
• Motor Drivers: Used in control circuits for DC motor speed and direction.
• Power Supplies: Acts as a key switching device in SMPS and inverter designs.

Applications:

• Audio Amplification: Drives large speaker loads with clean output power.
• Voltage Regulation: Used in both linear and switching voltage regulator stages.
• High-Current Switching: Ideal for industrial relays, solenoids, and lighting control systems.

Equivalent Models:

• 2SC5200: Popular high-power NPN transistor, complements 2SA1943 in amplifier pairs.
• TIP3055: Lower voltage and power version (60V, 90W) suitable for medium-load designs.
• BD243C: Medium-power substitute for lighter applications.

Package Includes:

• 1 × D718 (2SD718) 8A 120V 80W NPN High-Speed Switching Transistor (TO-3P)