Lab 03 Parameter Analyzer
Hung, Bill Chun Wai
Objectives
To
familiarize the use of the Agilent parameter Analyzer,
and to understand the linear and non-linear devices.
Procedure/Measurement
Report
1. Perform analysis of the
Circuit 1a, Circuit 1b, Circuit 2a, Circuit 2b with the Agilent
parameter Analyzer.
2.
Perform analysis on a diode in a chip with the Agilent
parameter Analyzer.
Results/Analysis
Circuit
1a
PSpice
Plot 1a.
Calculation:
The equivalent resistance of the circuit is 2k//4k + 0.67k = 2k. The plot of
the I-V plot should be a straight line. When the current through the circuit is
0mA, the voltage should be 0V. When the current through the circuit is 10mA,
the voltage should be V=IR=10mA x 2k = 20V.
The PSpice plot is consistence with the calculated value (20V),
and the experimental plot (next page) is also consistence with the calculated
value(20V).
Part 1b.
Circuit
1b
PSpice
Plot 1b
Calculation:
The DC voltage source gives an offset of 1.5V to the circuit. Besides the
voltage source, there is only one resistor. So the plot is a straight line.
When the current is 0A, the voltage is 0V + 1.5V = 1.5V because of the offset.
When the current is 10mA, the voltage is V=IR + 1.5V=10mA x 1k + 1.5V= 11.5V.
The
calculated value (11.5V) agrees with the PSpice plot
shown above. The experimental result also generates the same result, and the
plot of the experimental result is shown in the next page. The experimental
result also agrees with the calculated value (11.5V).
Part 2a.
Circuit
2a
PSpice
Plot 2a
1
Calculation:
the V2 (Vg) gives an offset to the circuit. When the current is 0mA, and the V2
(Vg) is 0V, the voltage across R4 and R3 (Vds) is 0V.
When the current is 10mA, and the V2 (Vg) is 0V, the voltage across and R3 (Vds) is V=IR = 10mA(1k + 10k//1k) = 19.1V.
The V2
(Vg) is 1V, the V2 (Vg) gives and offset of 1k/(1k+10k) = 0.09V. That’s the I-V
straight line curve when V2(Vg) is 0V shifted upward by 0.09V. When the V2 (Vg)
is increased by another 1V (2V total), the output voltage curve is shifted by 2
x 0.09V = 0.18V. That’s 1V increase in V2(Vg) results in an offset of 0.09V of
the output voltage. The voltage of V2 (Vg) of 0V to 5V is shown in the Plot.
The calculation
agrees with the PSpice plot. However, there was an
error while the experiment was conducted, and the experimental plot is shifted
upward more than predicted.
Part 2b
Circuit
2b Open Switch
PSpice
Plot 2b Open Switch
Circuit
2b Close Switch
PSpice
Plot 2b Close Switch
When the switch is open, the equivalent
resistance is 2k, and when the current through the resistors is 10mA, the
voltage is V=IR = 20V. This calculated results agrees with the PSpice Plot and the experimental I-V plot.
When the switch is closed, one the of 1k resistors is shorted out.
The resulted circuit is the closed circuit with only 1k equivalent resistance.
When the current is 10mA, the voltage is V=IR = 10K. This calculation agrees
with the PSpice plot as well as the experimental plot
shown on the next page.
Part 3.
Diode
When the Voltage across the
forward-biased diode is below the cutoff voltage, the diode is off. In other
words, the current through the diode is very low. Once the voltage across the
diode reaches the cutoff voltage, the diode acts as a virtual short circuit and
permits current to go through.
The ideal plot of the I-V curve
of a forward biased diode should be a step function, however, the experimental
plot obtained from the lab is not a perfect step function. This is because the
diode used in the lab is not a perfect diode.
Conclusions
Through
this lab, the use of the parameter analyzer is explored, and familiar circuits
of resistors, diodes are plotted. This gives us a general sense how to use the
parameter analyzer to perform analysis. This lab also introduce the use of PSpice different circuits.