Name: L Trung

ID: 41103857

Homework 3: PSPICE & MATLAB report

For my ID: m=7, n=5

Problem 1:

Drawing and simulating these following circuits in PSPICE we obtain the voltage at each

node and current on each brand as shown:

a/

b/

c/

Problem 2:

2.1:

a/ VTh = Vab open-circuit = 20n x

= 100 x 0.8 = 80 (V)

RTh = Requivalent when all sources are suppressed = 8 + 10//40 = 8 +

= 16 ()

IN =

=

= 5 (A)

b/

VTh

Using test signal method we obtain R equivalent

2.2:

Using the same method we obtain VTh, RTh, IN for the following circuits:

RTh = VTh

IN

VTh

RTh = VTh

IN = 5+0.3889 = 5.3889

VTh

Problem3:

Sketch the circuit in PSPICE we obtain:

RTh = VTh

IN

Running AC sweep for parameter RL we can plot the function of WRL.

Look at the diagram and by toggle cursor we can see that WRL is maximized when RL equals

23.401 , at that time WRL max equals 95.398 W

Problem 4:

4.1/

Vout is -15 V due to the VDC restraint of the Op-Amp in PSPICE (from -15V to 15V)

To have the Op-Amp function properly we should adjust this constraint from Property Editor

to be larger (-1000V to 1000 V for example)

Vout =-35 V

The Op=Amp

operates properly

The same situation happens with AC voltage source:

The graph is cut at two peaks by -15 V and 15 V lines

After adjusting the constraint, we obtain the following diagram:

We can see that after the constraint is removed, the Op-Amps functions properly,

|Vout|=3|Vin| and the two signals are different by in phase.

Problem 5:

5.1/

Using Matlab we obtain the transfer function of the desired filter:

H(w) =

=

Equate with the Sallen Key filtetr formula we obtain T1 = 4.5e-5, T2 = 2.25e-5

Choose R1 = 1k , R2 = 1k we obtain C1 = 4.5e-8, C2 = 2.25e-8

Realizing the filter in PSPICE we obtain the following circuit:

Which has the transfer function diagram as followed:

We can double-check by seeing that the cut-off frequency is at 5kHz (at this point, the

corresponding dB(Vout) is -0.3 dB

5.2/

Using the table provided in Analog Filter Design slides we can obtain these following values

(impedences and frequency are scaled already):

R1=R2=10k

L1=L2=0.86pH

C1=C3=3.28nF

C2=10.61nF

Realizing in PSPICE:

Same as 5.1, we now use AC sweep so that the transfer function diagram is obtained:

Cut-off frequency is at 3Khz