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.
| Type | Functional Characteristics | Application Examples |
|---|---|---|
| Junction FET (JFET) | Voltage-controlled depletion mode operation, low noise | Low-noise amplifiers, analog switches |
| Enhancement Mode MOSFET | Normally-off device, requires positive VGS to conduct | Power supplies, motor drives |
| Depletion Mode MOSFET | Normally-on device, requires negative VGS to block | Radio frequency amplifiers, load switches |
| Insulated Gate Bipolar Transistor (IGBT) | Combines MOSFET input with bipolar output, high current capacity | High-power industrial equipment, electric vehicles |
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.
| Parameter | Description and Importance |
|---|---|
| VDS (Drain-Source Voltage) | Maximum voltage rating between drain and source; determines breakdown tolerance |
| ID (Drain Current) | Maximum continuous current capacity; critical for power handling |
| RDS(on) | On-state resistance; impacts conduction losses and efficiency |
| VGS(th) (Threshold Voltage) | Voltage required to form channel; determines control signal compatibility |
| QG (Gate Charge) | Charge required for switching; affects switching speed and driver requirements |
| PD (Power Dissipation) | Maximum power handling capability; dictates thermal management needs |
| Manufacturer | Representative Product | Key Features |
|---|---|---|
| Texas Instruments | CSD18534Q5A | 60V, 4.2m RDS(on), automotive-grade |
| STMicroelectronics | STP55NF06 | 55A, 60V, high-speed switching |
| Infineon Technologies | IPB041N06N3 | 0.41 , 600V, TO-220 package |
| ON Semiconductor | NDS355AN | Depletion mode, 300mA, RF applications |
Key considerations include:
Current trends include: