The term FET (Field-Effect Transistor) is a broad category that includes various types of transistors where the conductivity between two terminals (source and drain) is controlled by an electric field applied to a third terminal (gate). MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is a specific type of FET that incorporates a metal-oxide-semiconductor structure in its gate region. Therefore, MOSFET is a subset of FETs distinguished by its gate structure.
The basic difference between FET and MOSFET lies in their gate structure and operation. FETs, in general, include various types such as JFETs (Junction Field-Effect Transistors) and MOSFETs. MOSFETs specifically utilize a metal-oxide-semiconductor structure in the gate region, which allows for efficient control of the transistor’s conductivity and enables high input impedance and low input current requirements compared to other types of FETs.
MOSFET stands for Metal-Oxide-Semiconductor Field-Effect Transistor. The term “FET” refers to the broader category of transistors that operate on the principle of field-effect, where an electric field controls the flow of current between source and drain terminals. MOSFETs are called FETs because they belong to this category and are distinguished by the use of a metal-oxide-semiconductor structure in their gate region, which enhances their performance and versatility compared to other types of FETs like JFETs.
We often use MOSFETs over other types of FETs because of their advantageous characteristics. MOSFETs offer high input impedance, low input current requirements, and the ability to switch rapidly with minimal power loss. These properties make MOSFETs ideal for applications requiring efficient power switching, amplification in audio and radio frequency circuits, and as fundamental building blocks in digital logic circuits and integrated circuits (ICs). Their compatibility with CMOS (Complementary Metal-Oxide-Semiconductor) technology also makes them widely used in modern semiconductor manufacturing.
The main difference between a FET (Field-Effect Transistor) and a conventional bipolar transistor (BJT – Bipolar Junction Transistor) lies in their fundamental principles of operation. FETs operate based on the control of current flow through an electric field applied to a semiconductor channel, without requiring significant input current to the gate terminal. In contrast, BJTs are controlled by current flowing through the base terminal, which modulates the current between the collector and emitter terminals. This difference results in FETs typically having higher input impedance, lower power consumption, and faster switching speeds compared to BJTs, making FETs advantageous for certain applications like high-frequency signal processing, digital circuits, and low-power devices.