SLiCAP LTspice

Install and configure LTspice for schematic capture

If you want to use LTspice as schematic capture program you also need to install and/or configure LTspice as schematic capture program for SLiCAP. To this end you need to:

  1. Install the latest version of LTspice

  2. Start LTspice

  3. On the menu bar click Tools > Control Panel. This will bring up the LTspice control panel:

    ../_images/LTspiceControlPanel.png

  4. On this control panel select the Netlist Options tab and select the options as shown below:

    ../_images/LTspiceControlPanelNetlistOptions.png

  5. Then select the Sym. & Lib. Search Paths tab and enter the full path to the “LTspice” subdirectory of your SLiCAP install path. This directory contains all the SLiCAP symbol definitions (‘.asy’ files) for LTspice:

    ../_images/LTspiceControlPanelSymbolPath.png

  6. Then select the Drafting Options tab and change the font size and deselect the “Bold” checkbox as shown below. If you want, you can also select different colors for your schematics.

    ../_images/LTspiceControlPanelFontSettings.png

Draw the circuit in LTspice

Knowledge of drawing circuits with LTspice is assumed.

  1. Open LTspice and select File > New Schematic from the menu bar. Place a component on the schematic by clicking the AND gate symbol on the tool bar or by pressing the “F2” key (default Hot Keys setting). This will bring up the Select Component Symbol menu. On this menu select the directory with the SLiCAP symbols from Top Directory drop-down select box, as shown below:

    ../_images/LTspiceSelectSLiCAPcomponent.png

    All SLiCAP symbol names start with “SL”!

  2. Place an independent voltage source “SLV”, a resistor “SLR” and a capacitor “SLC” and create the circuit depicted below:

    ../_images/myFirstRCnetwork_asc.png

    Please note:

    1. The node of interconnection of the resistor and the capacitor is labeled as out. Later we need to refer to this node. SLiCAP will name the voltage at this node V_out.
    2. A default ground symbol (node 0) has been used.
    3. The use of the spice directive .param: it defines symbolic or numeric values of parameters.

  3. Save the circuit myFirstRCnetwork.asc in the project directory.

  4. If you want to display the circuit on a SLiCAP output html page, you need to create an image file of it that can be rendered by a browser. A .png file is a good candidate. You can generate a PNG from a screen dump with a graphic file editor (Paint, Gimp, Photoshop, etc.). Here we assume that the graphic file myFirstRCnetwork_asc.png has been saved in the project directory. It is shown above.