PSPICE

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PSPICE?????

• Simulation Program with Integrated Circuit
  Emphasis

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CH8

• VARYING COMPONENT VALUES
• ??????

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• Example 14 demonstrates how easily PSpice can
  analyze the same circuit several times with a
  different value of a given component used in each
  analysis.
• We use Probe to illustrate graphically the
  varying behavior of the circuit as the component
  value changes.

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Example 14

• Use a global parameter as the value of the
  resistor in Fig. 65 (see Example 10) from 20 ? to
  100 ? in 20 ? steps. Then plot the value of Vc
  versus t for each of the resistor values.

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Fig. 65
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Solution

• We define the global parameter by adding the
  Param part from the Special library.

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Fig. 67 Schematic
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??PARAMETER??

• To define the global parameter, invoke the
  property editor on the Param component. Then,
  click the New button, and type the name of the
  global parameter in the dialog box. This creates
  a new property, with the name RESISTANCE, for the
  Param component. We then entered a default value
  of 20 ? for this new property. To have this
  propertys name and its value appear in the
  schematic, highlight the spreadsheet column with
  the new property and click the display button.
  Then choose Display Name and Value from the
  Display Format dialog.

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Fig. 81 Property
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Fig. 82a Specify the analysis1
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Fig. 82 Specify the analysis2
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PSpice-gtRun
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Fig. 83 Probe
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• Note that the analysis using the smallest value
  of resistance has the smallest damping ratio.