Trans MOSFET N-CH 800V 3.8A 3-Pin(3+Tab) TO-220# Technical Documentation: BUZ80A N-Channel Power MOSFET
Manufacturer : INFINEON
Component Type : N-Channel Enhancement Mode Power MOSFET
Primary Package : TO-220 (also available in TO-220FP)
Technology : Vertical DMOS, Planar Technology
---
## 1. Application Scenarios (≈45% of content)
### Typical Use Cases
The BUZ80A is a high-voltage, high-current N-channel MOSFET designed for power switching applications. Its robust construction and electrical characteristics make it suitable for:
- Switching Power Supplies : Used as the main switching element in offline SMPS (Switched-Mode Power Supplies), particularly in flyback and forward converter topologies operating from rectified mains voltage (up to 500V DC link).
- Motor Control : Employed in H-bridge configurations for DC motor drives, stepper motor controllers, and brushless DC motor drives in appliances and industrial equipment.
- Lighting Systems : Key component in electronic ballasts for fluorescent lighting and as a switching device in LED driver circuits.
- Audio Amplifiers : Used in the output stages of class-D audio amplifiers for efficient power conversion.
- Relay/Solenoid Drivers : For inductive load switching where high voltage transient protection is required.
### Industry Applications
- Industrial Automation : Motor drives, PLC output modules, and power distribution controls
- Consumer Electronics : CRT television deflection circuits, audio systems, and power adapters
- Renewable Energy : Inverters for solar power systems (low-power applications)
- Automotive : Auxiliary systems requiring high-voltage switching (non-safety critical)
- Telecommunications : Power supply units for network equipment
### Practical Advantages and Limitations
Advantages:
- High Voltage Rating : 800V drain-source breakdown voltage makes it suitable for off-line applications
- Low Gate Charge : Typical Qg of 30nC enables relatively fast switching speeds
- Avalanche Rated : Can withstand specified avalanche energy (EAS = 280mJ), providing robustness against voltage transients
- Low On-Resistance : RDS(on) of 1.5Ω (max) at 25°C minimizes conduction losses
- Wide Safe Operating Area (SOA) : Allows operation under high voltage and current simultaneously for short durations
Limitations:
- Moderate Switching Speed : Not optimized for very high-frequency applications (>100kHz typically)
- Thermal Considerations : Requires adequate heatsinking in continuous high-current applications
- Gate Sensitivity : Like all MOSFETs, susceptible to static discharge and requires proper gate protection
- Body Diode Characteristics : Intrinsic body diode has relatively slow reverse recovery, which can limit performance in some bridge configurations
---
## 2. Design Considerations (≈35% of content)
### Common Design Pitfalls and Solutions
Pitfall 1: Inadequate Gate Driving
- Problem : Underdriving the gate (insufficient gate voltage or current) leads to excessive RDS(on) and thermal issues
- Solution : Use dedicated gate driver ICs capable of providing at least 10V VGS and peak currents of 0.5-1A. Implement proper gate resistor (typically 10-100Ω) to control switching speed and prevent oscillations
Pitfall 2: Voltage Spikes During Switching
- Problem : Inductive kickback causing voltage spikes exceeding VDS(max)
- Solution : Implement snubber circuits (RC or RCD) across drain-source. Use fast recovery diodes in parallel for inductive loads. Ensure proper layout to minimize stray inductance
Pitfall 3: Thermal Runaway
- Problem : Inadequate heatsinking causing junction temperature to exceed maximum rating
- Solution : Calculate power dissipation (P = I² × RDS(on) + switching losses) and
