FET input characteristics

Aim: -

To design and simulate a FET input characteristics.

Procedure for creating schematic diagram and simulating it

1. Open EDWinXP x.xx from Start -> Programs -> EDWinXP Main

2. Invoke the Schematic editor by double clicking the Project -> Main page

3. Choose EDSpice Simulator from Preferences Menu

Loading/Placing of components

1. In Browser, Search FET and choose 2N3819, click on place button and place it on the screen.

2. Select Ground from Sources group and place it.

3. Select DC Power supply from Sources group and place it.

4. The components can be placed in the grids with 100 mils (.1") and snap of 50 mils (.05")in the required position by relocation.

5. It is possible to use the customized keyboard keys for easy placement of components

Say press G for ground, E for DC Power supply, e.t.c

Routing Connections

1. The connection between components can be made by Tools -> Connections -> Connect components (First Function tool) {Connect the wires from pin to pin according to the circuit diagram.} while asked for entering Net name, give suitable names

2. Select Tools->Connections->Connection properties (Seventh function tool) -> Click on any connection and name it as required.

#Do not rename SPL0 (Ground)

Giving values

1. Tools -> Components -> Component properties -> Change simulation parameters->Select any component and change it values.

Initial settings

# DC Transfer function Analysis

2. Click on the DC Power Supply

A window is pops up

3. Enter following values

DC and Transient analyses value of the source [DC/TRAN] 1 volts

4. Click Accept

5. Similarly Set VDC/2 as 0 volts and VDC/3 as 10 volts

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.

1. Simulation -> Preprocess

2. For setting up simulation time and analysis types, select Simulation menu, choose Analysis.

3. In the window pops up, select DC Transfer function analysis from tree view.

4. Enter following values:

First Source : VDC/1 [V2]

Start voltage : -5

Stop voltage : 0

Step : 100m

Results : Select waveform from drop down menu.

5. Click on Accept.

6. Expand the DC Transfer function tree view and select Waveform viewer

7. Mark branch voltage of second voltage source (dummy voltage source) VDC/2

8. Click on Accept.

9. Select DC Transfer function analysis

10. Run Analysis by clicking on Run button

11. Verify the results