To simulate the MOSFET input characteristics.

Components required

NMOSFET- NMESFET (1), DC Voltage Source – VDC (3), Ground - SPL0 (1)

Circuit Diagram


1.Draw the circuit diagram after loading components from library. A DC source with 0 V is placed as the dummy voltage source to obtain the current waveform. Wiring and proper net assignment has been made. The values are assigned for relevant components. The circuit is preprocessed. The test points and waveform markers are placed in input and output of the circuit.  DC Transfer Analysis parameters have been set. The analysis is executed and output waveform is observed in Waveform Viewer.

2. To proceed with the simulation, the steps are as follows

Select Tools → Components → Component properties→ Change simulation parameters→ Click on the required component and change its values.

The values to be provided to the components are

NMOSFET     : NMESFET (Click on the Set up Model of the Model Type. Click on Accept to get the default values assigned)

VDC/1                        : 0V

VDC/2                        : 0V

VDC/3                        : 10V

Note: For input/output characteristics plot of BJT, FET, MOS etc, it is not necessary to place a waveform marker in the diagram. Its because the sweep variable of the VI parameters are being plotted. The current through a net can be obtained by enabling the Vx#branch in the waveform. Please ensure the connectivity of dummy voltage source having (0V) for obtaining the direction of current.  


3. For setting up simulation time and analysis types, select Simulation menu, choose Analysis. In the window pops up, select DC Transfer function analysis from tree view.

Enter following values:

First Source                             : VDC/1 [V2]

Start voltage                           : -5V

Stop voltage                            : 5V

Step                                        : 100m

Results                                    : Select waveform from drop down menu.


4. Click on Accept. Expand the DC transfer function Analysis and select Waveform viewer, Select dummy voltage source branch. Mark branch voltage of second voltage source (dummy voltage source) VDC/2. Click on Accept. Select DC Transfer function analysis. For plotting the DC transfer function analysis, the current waveform marker/plot (Vx#branch) should be taken from the dummy voltage source - VDC (additional dc voltage source included in the path of current flow having dc voltage set to 0. Run Analysis by clicking on Run button.