Programming instructions

Basic Components

Multisim Component Reference Guide 2-22 ni.com

These expressions are derived by applying appropriate numerical integration to the

characteristic equation of the capacitor.

2.7.4 AC Frequency Model

For the small-signal analysis, the capacitor is modeled by an impedance whose imaginary

component is equal to:

where:

f = frequency of operation

C = capacitance value

2.7.5 Changing a Placed Capacitor’s Value

 To change the value, and other parameters of a placed capacitor:

1. Double-click on the capacitor and select the Value tab.

2. Select the desired capacitance from the Capacitance(C) list. If it is not there, type the value

you want.

3. Select the desired tolerance from the Tolerance list, or type in a value.

4. Optionally, enter information in the Component Type (for example, ceramic) and

Hyperlink fields.

5. Optionally, enable the Additional SPICE Simulation Parameters field described below:

•

Initial Conditions checkbox — enable and then enter an initial voltage charge for the

capacitor.

6. Optionally, change the Layout Settings as described below:

•

Edit Footprint button — click to display the Edit Footprint dialog box where you can

select a new

Footprint and Manufacturer.

Note For information on placing capacitors, and information on how to edit footprints, refer

to the

Multisim User Guide or the Multisim helpfile.

ComponentRef.book Page 22 Thursday, December 7, 2006 10:12 AM