Characteristics of E-MOSFET
There are two types of characteristics of E-MOSFET- drain characteristics and transfer characteristics. Both type of E-MOSFET, i.e., n-channel E-MOSFET and p-channel E-MOSFET have these characteristics, and are discussed below:
Characteristics of N-Channel E-MOSFET
Characteristics of n-channel E-MOSFET refers to the curves which relate the current and voltage of device with each other. There are mainly two types of characteristics in n-channel E-MOSFET:
- Drain Characteristics: These curves provide the relationship between drain current (ID) and drain-to-source voltage (VDS). When different values of drain current and drain-to-source voltage are plotted on graph, it gives respective values of gate-to-source voltage (VGS). These characteristics are also called as V-I characteristics of a curve.
From the graph shown below, it is observed that when the positive value of VGS is increased, the current ID will also increase. This graph consists of two regions: non-saturated region and saturated region. The non-saturated region of the curve is also called as ohmic region, in this region when drain current is increased then subsequently the value of drain-to-source voltage also increases.
Ohmic region lasts till when the value of drain-to-source voltage reaches a threshold value called as threshold voltage (VTN). After this voltage saturation of n-channel E-MOSFET takes place. Hence, the region of curve after threshold voltage is achieved is called as saturated region.
- Transfer characteristics: These curves provide the relationship between drain current (ID) and gate-to-source voltage (VGS). When different values of drain current and gate-to-source voltage are plotted on X- axis and Y-axis respectively, it provides different values of drain-to-source voltage (VDS). These curves are also called as transconductance curves.
From the transfer characteristics of n-channel E-MOSFET shown below it is observed that when the value of gate-to-source voltage is below the threshold voltage (VTN) then no drain current flows. When gate-to-source voltage is increased, and it reaches to threshold voltage then drain current (ID) starts flowing.
Characteristics of P-Channel E-MOSFET
Characteristics of p-channel E-MOSFET refers to the curves which relate the current and voltage of device with each other. There are mainly two types of characteristics in p-channel E-MOSFET:
- Drain Characteristics: These curves provide the relationship between drain current (ID) and drain-to-source voltage (VDS). When different values of drain current and drain-to-source voltage are plotted on graph, it gives respective values of gate-to-source voltage (VGS).
From the graph shown below, it is observed that when the negative value of VGS is increased, the current ID will also increase. The graph of p-channel E-MOSFET consists of two regions: non-saturated region and saturated region. The non-saturated region of the curve is also called as ohmic region, in this region when drain current is increased then subsequently the value of drain-to-source voltage also increases.
In non-saturated or ohmic region Enhancement MOSFET works as amplifiers. Ohmic region lasts till when the value of drain-to-source voltage reaches a threshold value called as threshold voltage (VTP). After this voltage p-channel E-MOSFET works under saturated region. Hence, the region of curve after threshold voltage is achieved is called as saturated region. In this region Enhancement-MOSFET works as a voltage-controlled resistor.
- Transfer characteristics: These curves provide the relationship between drain current (ID) and gate-to-source voltage (VGS). When different values of drain current and gate-to-source voltage are plotted on X- axis and Y-axis respectively, it provides different values of drain-to-source voltage (VDS).
The transfer characteristics of p-channel of Enhancement type MOSFET is the mirror image of transfer characteristics of n-channel E-MOSFET. In this curve the value of drain current increases when the value of gate-to-source voltage decreases.
E-MOSFET
Enhancement MOSFET which is commonly called as E-MOSFET is a type of field effect transistor which is used mainly in voltage-controlled devices. It is a unipolar device, i.e. device in which conduction of current takes place either by electrons or holes. It is a three-terminal device which is mainly used as amplifier or in switching devices.
This type of transistor can be used both in analog and digital devices. These transistors are more popular than Bipolar junction transistors due to less power dissipation and negligible leakage current. These are smaller in size and hence find its application in integrated circuits (ICs).
Table of Content
- Enhancement Type MOSFET
- Symbol
- Types of E-MOSFET
- N-Channel E-MOSFET
- P-Channel E-MOSFET
- Working
- Characteristics
- Difference Between Depletion MOSFET and Enhancement MOSFET
- Features of
- Advantages
- Disadvantages
- Applications