Sweep Properties

Every Graph Sheet in Eclipse contains its own definition regarding how the circuit is to be swept. The Sweep Properties dialog box shown below contains this definition.

sweep.gif (8561 bytes)

The Sweep Properties dialog box contain multiple fields requiring you to input numeric data. Pressing <TAB> after entering data will automatically move the cursor to the next logical input field. The fields utilize the current default units: resistance, inductance, capacitance, frequency, time and length where appropriate. When the cursor is in a field utilizing default units, the dialog box will indicate the specific units for that field. When you have finished entering data into these fields you may choose OK or Cancel to accept or discard the entries. In either case the dialog box will be closed.

Choosing a Sweep Type

The Type list box allows you to choose the method by which your circuit will swept:

Frequency Sweeps the circuit over the range of specified frequencies (default method)
Element parameter Sweeps the specified circuit element parameter over the range of values at the frequency indicated
Variable Sweeps the specified User Variable over the range of values at the frequency indicated

You must select one of the methods by clicking on the list box and then choosing one of the menu items. The default method is Frequency sweep.

Choosing a Sweep Style

The Style list box allows you to specify whether the sweep will be entered as a Start/Stop or Center/Span set of values. The Start/Stop method defines the starting and ending sweep values, while the Center/Span method specifies the arithmetic center and total span. You must select one of the styles by clicking on the list box and then choosing one of the menu items. The default method is Start/Stop.

Start Field

The sweep starting value. Used in conjunction with the Stop Field. This field is affected by the Default Units.

Stop Field

The sweep ending value. Used in conjunction with the Start Field. This field is affected by the Default Units.

Center Field

The arithmetic center of the sweep range. Used in conjunction with the Span Field. This field is affected by the Default Units.

Span Field

The total span of the sweep range. Used in conjunction with the Center Field. This field is affected by the Default Units.

Res And Step Fields

These fields are mutually exclusive, i.e., entering data in one causes data in the other to be cleared. The Res ( resolution ) field specifies the size of a step in the given sweep, whereas, the Step field allows you to specify the total number of steps. The Res field is affected by the Default Units.

Mode List Box

This list box controls whether the sweep will be spaced in linear (LIN) or logarithmic (LOG) increments.

List Field

The List field allows you to specify a list of arbitrary values that will be combined with the Start/Stop or Center/Span sweep values during analysis.

Ref And Elem Fields: Sweeping Elements

An Element Sweep allows you to graph output data versus an element parameter at a single frequency. Any numeric element parameter may be swept. You must specify the element parameter to be swept and the stationary frequency in the Ref and Elem fields respectively.

Ref And Var Fields: Sweeping User Variables

A Variable Sweep allows you to graph output data versus a User Variable at a single frequency. You must specify the frequency and the User Variable in the Ref and Var fields respectively. The Frequency Default Units affect the Ref fieldProgramUnitsContext. The Start/Stop and Center/Span fields will define the range over which the User Variable will be swept.

Changing the Sheet's Name

You can change the name displayed on the sheet's tab by clicking the right mouse button on the sheet tab and entering a new name in the resulting dialog box. The name should be unique with respect to all other tabs.

Enabling/Disabling Sweep information

You may enable/disable all or part of the sweep information in the dialog box by selecting the appropriate check box under the category, Use. If the check box is cleared then the corresponding information will not be used.

Adding a Sheet Title

You may specify a title that will appear on printed sheets by entering the desired information in the Title field.

Use Global Sweep

Each graph sheet has a local (private) sweep definition that can be used during analysis. Additionally, there is a global sweep definition that is shared by any sheet having the Use Global Sweep box checked. When checked, the sheet uses the global definition during analysis; otherwise, the local definition is used. By default, each new sheet is created with the global sweep selected. If you copy an existing Graph Sheet, the local information in the source sheet will be duplicated in the destination sheet.

Transferring Sweep Definitions

The global sweep definition can be copied to a sheet's local definition, or vise versa. Click the Transfer button and then select the displayed menu item to complete the transfer of information.

General Sweep Information

Eclipse supports the concept of BlackBox elements (See the Element Library). Each BlackBox references its own data file of frequency dependent parameters. The frequencies defined in the Sweep Properties dialog box do not have to match the frequencies in the files. When the circuit is solved at frequencies within the frequency range of the file data, linear interpolation of the data is used. Linear extrapolation is used at frequencies outside the data file range. Extrapolation outside a data file's range generally results in useless data and should be avoided if possible.