Cadence PSPICE SCHEMATIC Instrukcja Użytkownika Pobierz pdf (Strona 14)

Figure 18: PSpice A/D with a plot of the voltage in the potential divider.

moved across the graph using the mouse or the ← and → keys. A dialogue box shows the

numerical values at the intersection of the cross-wires. Experiment with the left- and right-

click buttons on the mouse to see how the two sets of cross-wires can be manipulated back and

forth. The right-hand part of the lower toolbar becomes active for the cursors. It helps you to

locate maxima, minima or other features. The rightmost button generates a label to show the

values at the selected point.

You can annotate the graph with your own text labels. Choose Plot > Label > Text or use

the button. Type the required label and Close. Move the text box to the desired location and

left-click the mouse to place it.

3.6 Vary the load resistor – Parametric sweep

You very often want to investigate how the performance of a circuit depends on the value of

a particular component. You therefore want to run the simulation several times for different

values of that component so that you can compare them. This is called a parametric sweep and

is clumsy in OrCAD. However, it is used so often that you need to learn how to do it.

Stick with the potential divider. Suppose that V1 and R1 act as a Thévenin voltage source

and that R2 is a load. Let’s investigate how the voltage that we plotted in ﬁgure 18 depends on

the value of the load resistor.

There are three steps for using a parameter: create the parameter, which is stored in a

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Cadence PSPICE SCHEMATIC Instrukcja Użytkownika Strona 14