1. Overview

Field-Effect Transistors (FETs) and Metal-Oxide-Semiconductor FETs (MOSFETs) are voltage-controlled semiconductor devices that regulate current flow through an electric field. As fundamental components in modern electronics, they offer advantages such as high input impedance, low power consumption, and fast switching capabilities. Single discrete FETs/MOSFETs are widely used in power management, signal amplification, and switching applications across industries.

2. Main Types and Functional Classification

3. Structure and Composition

A typical MOSFET structure includes three terminals: Source, Gate, and Drain. The gate is insulated by a thin layer of silicon dioxide (SiO₂), forming a capacitive control interface. The channel between source and drain is formed in a silicon substrate. Advanced devices use materials like silicon carbide (SiC) or gallium nitride (GaN) for higher performance. Packaging options include TO-220, DPAK, and SOT-23 for different thermal and space requirements.

4. Key Technical Specifications

5. Application Fields

• Consumer Electronics: Mobile phone chargers, notebook power adapters
• Industrial: Motor drives, uninterruptible power supplies (UPS)
• Automotive: Electric vehicle (EV) battery management systems, HEV inverters
• Telecommunications: Base station power amplifiers, optical network transceivers
• Renewable Energy: Solar micro-inverters, wind turbine converters

6. Leading Manufacturers and Products

7. Selection Guidelines

Key considerations include:

• Voltage and current requirements under operating conditions
• Thermal performance (R_DS(on), package thermal resistance)
• Switching speed vs. conduction loss trade-off
• Gate drive compatibility with control circuitry
• Environmental factors (temperature, vibration, humidity)
• Cost-performance balance for volume production

8. Industry Trends

Current trends include:

• Adoption of wide bandgap materials (SiC, GaN) for higher efficiency
• Advanced packaging technologies (double-sided cooling, copper clip)
• Integration with gate drivers and protection circuits
• Miniaturization through trench and shielded gate structures
• Development of automotive-qualified devices for EVs and ADAS