Documentation

Simulation - Define PWL Source

3 min read

This device can be used to describe a piece wise linear source. A PWL source can describe any arbitrary wave shape in terms of time voltage or time current pairs.

Use this when editing a Part to define the Part as a PWL Source.

Use this on a PWL Source or PWL Current Source component in a schematic design to specify the time voltage or time current pairs respectively.

These parts have their Spice Type Built-in Function set to Source - PWL Voltage or Source - PWL Current.

Shortcuts

Default Keys: F7

Default Menu: Simulation

Command: Edit Spice Value/Model

How To Add A PWL Source Component

Once you have a circuit that you wish to simulate, add a PWL source device to provide a stimulus for the circuit. There are various ways to add a PWL Source device to a Schematic Design:

  1. From the Parts toolbar, click on the Sources pop-up (battery symbol) to display the Sources toolbar. Click on the PWL Source or PWL Current Source buttons.
  2. From the Parts Browser, click on the Sources category to display a list of sources. Drag the any of the part names mentioned in method 1 above, into the design. Note: This method may not work if you have changed the part categories.
  3. Use Component from the Insert menu to add Parts with the names mentioned above in method 1, from the SPICE library.

Whichever method is used, you should be presented with a Voltage or Current PWL Source component to place in the design.

How To Define A PWL Source

In a Schematic Design, select the PWL Source device(s) that you wish to change. Press F7 or use the Edit Spice Value/Model option from the Simulation menu, or from the shortcut menu.

From a Parts Library edit the required Part. Press the Edit Spice button on the Details tab. Make sure the Built-in Function is set to Source - PWL Voltage or Source - PWL Current and press the Edit Value button.

In both cases the following dialog will be displayed:

Specify the time and voltage/current value pairs. When defined in this way PWL sources are limited to 256 points. Much larger PWL sources may be defined. See the Device Reference in the Pulsonix-Spice Users Guide for more information.

Editing Multiple Components

If any of the fields are set to then some of the components you are changing have different values for that field. Clear this field and enter the required value for all components, or leave as to tell components to keep their original values for that field.

AC Source | DC Source | Edit Device Type | Waveform Generator

Backlinks