Setting up Enhancement mode MOSFET in PSPICE

1. In the Schematics window, click on Draw on the menu bar -> Get New Part . You will get the following dialog box

2. Select Libraries to get the following dialog box. Select breakout.slb library as shown in the image below.

For Nmos Enhancement mode Select part MbreakN as shown

For Pmos Enahancement mode Select part MbreakP

Select OK and Place & Close

3. Place the part at the desired location and select it as shown

4. Select Edit from the menu bar and choose Model from the menu to get the following Dialog Box

5. Select Edit Instance Model (Text).. to get the following window

6. Type in the parameters you want to specify with the corresponding values

Following parameters can be specified for a Enhance mode mosfet (These parameters are labeled exactly in the same manner for both PMOS and NMOS)

(a) (a) Threshold Voltage as Vto = 1

(b) (b) Proportionality Constant Kp = 25u

(c) (c) Length L=1

(d) (d) Width W =1

(e) (e) g Gamma = 0

(f) (f) f Phi = 0

*The values given above and in the image below are just for understanding purpose. The actual values will depend on the problem you are trying to solve. You do not need to specify all the parameters , only the ones required by the problem.There are more parameters which can be specified for a MOS. But those are beyond the scope of this course.

7. Select OK after typing in the values of the required parameter and build the rest of the circuit.

Setting up BJT in PSPICE

The steps to setup BJT are almost same as that of MOSFET with following changes:

In step 2, after selecting “Breakout.slb” library choose

QbreakN for npn transistor

QbreakP for pnp transistor

The parameters that can be specified for a BJT are as follows:

(g) (g) b as BF = 200

(h) (h) Reverse Saturation Current IS = 1e-15

(i) (i) Early Voltage VAF = 130