Spectrum Software
Industrial Strength Simulation




Spectrum Software has released Micro-Cap 11, the eleventh generation of our SPICE circuit simulator.

For users of previous Micro-Cap versions, check out the new features available in the latest version. For those of you who are new to Micro-Cap, take our features tour to see what Micro-Cap has to offer.




Easily Overlooked Features


This section is designed to highlight one or two features per issue that may be overlooked because they are not made visually obvious with an icon or a menu item.

Connecting Nodes
The basic connection between nodes occurs through the use of the wire object. It is the obvious and often, easiest method for connecting nodes. There are two wire modes available: orthogonal and diagonal. There is no difference between these two modes except for the appearance of the wire on the schematic. The choice between the two modes would be purely for aesthetic reasons.

However, due to the size or configuration of a circuit or the fact that it may span multiple pages, the two wire modes may not be practical or available for use. For this reason, there are three other methods available for connecting components.

Naming Nodes with Grid Text
In addition to the automatic numbering of the nodes that Micro-Cap performs, a node may also be designated with a text name. If two nodes are defined with the same text name, then those two nodes will be connected on the schematic. To name a node, enter Text mode while in the schematic. Click on a wire or a pin of a component. The text dialog box will appear, and a node name can be entered. The node name must start with a letter or an underscore and must not be a reserved variable or operator name. For a text string to designate a node name, the bottom left corner of the text string must be attached to the wire or the pin of a component.

The Tie Component
Another method for connecting nodes is through the Tie component. The Tie component is available under the Component menu in the Analog Primitives / Connectors section. The Tie component is simply attached to a node just like any other component. It has one attribute which is the PART attribute. Any Ties that share the same PART attribute definition will be connected together. A Tie that does not have another matching Tie will have no effect on the node.

The .TIE Statement
The .TIE statement operates in a different manner than the previous two methods. The .TIE statement connects together all of the specified <pin name> pins of the specified <part name> parts. This conveniently connects common pins for the same type of components. It is normally used for power, clock, reset, and preset pins. The syntax for the statement is:

.TIE <part name> <pin name>

Note that <part name> is the general part name from the Component library not the PART attribute definition. Examples of this statement are:


The first example connects the CLKB pin of all JKFF components in the schematic. The second example connects the VCC pin of all LF155 components in the schematic. The LF155 will connect only the LF155 components taken from the Analog Library section of the Component menu. An Opamp component, from the Analog Primitives section, that is defined with a LF155 model statement would not be effected because the <part name> is Opamp in that case.
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