Four Types of MOSFETs

Four Types of MOSFETs

MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) can be classified into four basic types according to their channel type and operating mode.

1. N-Channel Enhancement MOSFET

Abbreviation: N-Channel Enhancement MOSFET (N-MOS)

Characteristics:

• The most widely used type of MOSFET.
• Requires the gate-to-source voltage (VGS) to exceed the threshold voltage (Vth) in order to turn on.
• Normally remains OFF when VGS = 0 V.

Applications:

Switching power supplies

• DC-DC converters
• Motor drives
• Battery protection circuits

2. P-Channel Enhancement MOSFET

Abbreviation: P-Channel Enhancement MOSFET (P-MOS)
Characteristics:

• Turns on when the gate voltage is sufficiently lower than the source voltage.
• Normally remains OFF when VGS = 0 V.

Applications:

• High-side switches
• Power management circuits
• Load switches

3. N-Channel Depletion MOSFET

Abbreviation: N-Channel Depletion MOSFET
Characteristics:

• Conducts when VGS = 0 V.
• Applying a negative gate voltage gradually turns the device off.
• Considered a normally ON device.

Applications:

• Constant current sources
• Specialized analog circuits
• Startup circuits

4. P-Channel Depletion MOSFET

Abbreviation: P-Channel Depletion MOSFET
Characteristics:

• Conducts when VGS = 0 V.
• Applying a positive gate voltage gradually turns the device off.
• Less commonly used.

Applications:

• Specialized analog circuits
• Constant current circuits
• Comparison of the Four MOSFET Types

Type Default State (VGS = 0 V) Turn-On Condition Popularity

MOSFET

Four Types of MOSFETs

                              MOSFET
                                        │
┌─────────────┴─────────────┐
│                                                                               │
Enhancement Mode                         Depletion Mode
(Normally OFF)                                 (Normally ON)
│                                                                   │
┌───┴───┐                                 ┌───┴───┐
│                    │                                  │                     │
N-Channel P-Channel                N-Channel P-Channel

For technical presentations or marketing purposes, it is recommended to focus primarily on N-Channel Enhancement MOSFETs and P-Channel Enhancement MOSFETs, as more than 90% of today’s power MOSFET market consists of these two types.

Related concepts:

MOSFET

• N-Channel Enhancement MOSFET
• P-Channel Enhancement MOSFET
• N-Channel Depletion MOSFET
• P-Channel Depletion MOSFET
•