Topological Conflicts
This section describes topological conflicts
Topological conflicts in the circuit are: state degenerations and source degenerations. These conflicts are hard to analyze and to simulate. In most cases, as a result of circuit analysis, an infinite current/voltage can occur.
State degenerations are degenerated capacitances and inductances in the circuit. A capacitor connected in parallel with a voltage source is degenerated in Figure 1. An inductor connected in series with a current source is degenerated in Figure 1. Degenerated capacitors and inductors are replaced by the resistors with a resistance value equal to the specified value of capacitance or inductance, respectively.
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There are two types of source degenerations: Direct degeneration of independent sources and direct degenerations of independent sources with zero sources. Zero sources are open and closed switches. An open switch is a current source with zero current, while a closed switch is a voltage source with zero voltage.
Direct degenerations of an independent voltage source cannot be resolved. Compilation of such a circuits will fail and an error report will be printed out.
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Degenerations of independent sources with zero sources (open and closed switches), shown in Figure 5, will be automatically solved as following: a closed switch connected in parallel with a voltage source will be treated as an open switch, while an open switch connected in series with an independent current source will be treated as a closed switch. In other words, closing a switch that is connected in parallel with an independent voltage source has no effect, and opening a switch connected in series with an independent current source has no effect on the circuit. In case of these types of degenerations, a warning message will be generated during compilation.
![](../Images/topological_conflicts_05.jpg)
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Sometimes this type of the degenerations can occur in regular circuits when a coupling component is inserted. In these cases, a correct snubber or shunt circuits have to be used.