CMPE3403 Page 1 of 3
Assignment Week #1 Fall 2008
1. For the following circuit and your assigned component values find the Thevenin
equivalent Vth and Rth and the Norton equivalent IN and RN. Also use SPICE to model
the circuit and connecting the voltage source test circuit to the terminals do a DC Sweep
from a high enough voltage such that the current out of the terminals is negative (flows in
to the terminal) to 0V. Print a graph of current flowing out of the circuit terminal (Y
coordinate) versus test voltage (X coordinate) and turn in with your assignment. Verify
on the graph that the test voltage for 0 current Voc agrees with Vth, that the current
flowing out of the circuit terminals I short circuit Isc for 0V test source agrees with IN and
lastly that Voc/Isc = Rth.
2. For the following circuit the transfer function H(j) may be written as:
21
2211
11
1
11
1
jj
CRjCRj
jH
and the magnitude of H(j) which is what you plot in the Bode plot is:
2
2
2
1
11
1
jH
where
11
1
1
CR
and
22
2
1
CR
and the angle of H(j) is:
21
arctanarctan
jH
For your values of R's and C's sketch the dB magnitude (20Log10(|H(j)|) and angle
Bode plot of the transfer function. Remember the X coordinate must have a log scale
for the Bode plot as well. Add a AC source at the input and a resistor at the output and do
an AC analysis using SPICE from = 1 radian per second to = 109 radian per second.
Use the SPICE graph functions to graph the dB magnitude of Vin/Vout versus on a log
scale ( = 2f) and angle of Vin/Vout versus . Verify that the simulation agrees with
your Bode plot sketch. The E's have to be set equal to 1.
CMPE3403 Page 2 of 3
Assignment Week #1 Fall 2008
