Infineon BUZ80A Power MOSFET: Datasheet, Pinout, and Application Circuits

The Infineon BUZ80A stands as a classic N-channel enhancement-mode power MOSFET, renowned for its robustness and efficiency in switching applications. This article delves into its key specifications, pinout configuration, and typical circuits to provide a comprehensive overview for engineers and enthusiasts.

Datasheet Overview and Key Specifications

The BUZ80A is designed to handle significant power levels, making it a go-to component for amplifiers, power supplies, and motor control. Its primary specifications include:

Drain-Source Voltage (V_DS): 800V, allowing it to operate in high-voltage circuits.

Continuous Drain Current (I_D): 8A, suitable for medium to high-power applications.

On-Resistance (R_DS(on)): 1.5Ω (max. at I_D = 4A, V_GS = 10V), which determines the conduction losses and overall efficiency.

Gate Threshold Voltage (V_GS(th)): 2-4V, a standard range for easy driving by most logic-level and PWM controllers.

Power Dissipation (P_D): 125W (with sufficient heatsinking), indicating its ability to manage heat under load.

These parameters highlight the device's core strength: switching high voltages and currents with relative simplicity and control.

Pinout Configuration

The BUZ80A is commonly available in the TO-220 package, a industry-standard through-hole design that facilitates easy mounting on a heatsink. The pinout is standard for many TO-220 MOSFETs:

1. Gate (G): This is the control pin. A voltage applied between the Gate and Source terminals creates an electric field that allows current to flow between the Drain and Source.

2. Drain (D): This is the output pin connected to the main load. It is typically attached to the positive high-voltage rail.

3. Source (S): This is the common or ground reference pin for both the power circuit and the gate driving signal.

Application Circuits

The BUZ80A excels in various power electronics applications. Two classic examples are:

1. Low-Side Switch Circuit:

This is one of the most common configurations. The MOSFET is placed between the load and ground. The load (e.g., a motor, solenoid, or lamp) is connected to the positive supply rail (V_DD), and the Drain of the BUZ80A. The Source is connected directly to ground. A gate driver circuit (which could be a simple microcontroller pin with a series resistor or a dedicated driver IC) controls the switching. When the gate voltage exceeds the threshold, the MOSFET turns on, completing the circuit and powering the load. This circuit is fundamental for PWM-based speed control of DC motors.

2. Simple Switch-Mode Power Supply (SMPS):

The BUZ80A can serve as the main switching element in offline flyback or forward converter topologies. In a simplified flyback converter, the MOSFET is switched on and off at a high frequency by a dedicated PWM controller IC. This action stores energy in the transformer's primary winding when the MOSFET is on and releases it to the secondary output circuit when it's off. The 800V V_DS rating is critical here to withstand the voltage spikes generated by the transformer's leakage inductance.

ICGOODFIND Summary

The Infineon BUZ80A is a high-voltage, robust power MOSFET that has proven its reliability over decades. Its high 800V drain-source voltage rating and 8A current handling capability make it an excellent choice for demanding switching applications, including SMPS, motor drives, and electronic ballasts. While newer technologies may offer lower R_DS(on), the BUZ80A remains a dependable and widely supported component for both new designs and repairs.

Keywords:

Power MOSFET

High Voltage Switching

TO-220 Package

Application Circuits

Datasheet