Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs)

The Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) is currently attracting the most attention among transistors.
There are two types of MOSFET: N channel (See Fig.3-4(a) Nch below) and P channel (See Fig.3-4(b) Pch below).
Nch is widely used for AC/DC power supplies, DC/DC converters, inverter equipment, etc., whereas Pch is used for load switches, high-side switches, etc.
The differences between the bipolar transistor and the MOSFET are shown in Table 3-1.

Symbol and operation of N-channel MOSFET
Fig. 3-4(a) Symbol and operation of N-channel MOSFET
Symbol and operation of P-channel MOSFET
Fig. 3-4(b) Symbol and operation of P-channel MOSFET
BJT(Current-driven device) MOSFET(Voltage-driven device)
  • Low input impedance
  • Large reverse transfer capacitance
  • Narrow safe operating region
  • Enables low-voltage operation (On voltage is 0.6-0.7 V)
  • High input impedance
  • Small reverse transfer capacitance
  • Wide safe operating region
  • Low gate  power consumption
  • Easy driving

Table 3-1 Comparison of BJT and MOSFET

Chapter III : Transistors

Types of Transistors
Bipolar Transistors (BJTs)
Bias Resistor Built-in Transistors (BRTs)
Junction Field-Effect Transistors (JFETs)
Differences between BJT and MOSFET
Structure and Operation of MOSFET
MOSFET Performance Improvement: Decision Factors of RDS(ON)
MOSFET Performance Improvement: Approach to Low RDS(ON)
MOSFET Performance Improvement: Super-Junction MOSFETs (SJ-MOS)
Summary of MOSFET Features by Structure
Performance of MOSFETs: Drain Current and Power Dissipation
Performance of MOSFETs: Avalanche Capability
Performance of MOSFETs: Characteristic of Capacitance
Performance of MOSFETs: Safe Operating Area(or Area of Safe Operation)
Insulated-Gate Bipolar Transistors (IGBTs)
Operation of Insulated-Gate Bipolar Transistors (IGBTs)
Performance Improvement of IGBTs: Evolution of Vertical Design
What are RC-IGBTs and IEGTs?
Application of IGBTs
Comparison of Forward Characteristics of IGBTs and MOSFETs
Comparison of Transistors by Structure
Datasheets of MOSFET: Maximum Ratings
Datasheets of MOSFET: Electrical Characteristics
Datasheets of MOSFET: Capacitance and Switching Characteristics
Datasheets of MOSFET: Body Diode

Related information