Terminals and Extraction
All source and sink terminals are extracted either as a group or individually in accordance with the pin groups specified on the components. These pin groups can be overridden by selecting Merge Sources and Merge Sinks (e.g., you can leave the Merge Sources option unselected and use the pin groups to define multiple source groups for extraction on a component. See: Grouping Pins.). If every individual source needs to be extracted, remove all the pin groups for that component and clear the Merge Sources option.
When modeling power and ground planes, you can choose from the following different solution options:
You may not be interested in detailed modeling of power and ground planes but may still want to include their effects on the inductance, capacitance and resistance of the signal traces. TPA then models the induced currents on the power and ground planes as it calculates the inductance, capacitance and resistance of the signal traces.
TPA allows you to treat the plane as being grounded at its terminals. In this case, the planes are suppressed in the resulting equivalent circuit model. For a more detailed analysis, you can treat the planes as "active" conductors. The different modeling options are described in more detail below.
Ground Pwr/Grnd Nets @ Terminals
TPA adds a ground connection to each terminal in the power and ground planes. This is equivalent to assuming that every solderball and bondwire connected to the plane is attached to a high-quality electrical ground. TPA then models the induced currents on the power and ground planes as it calculates the inductance of the signal traces.
The terminals in power and ground planes are exposed in the resulting Spice circuit model rather than just being grounded.
Active Mode generates the most accurate results, because it allows you to control how the plane terminals are actually connected. The drawback is the time it takes to analyze the additional terminals.
Use Active Mode when:
- You require a detailed modeling of non-ideal power and ground planes effects, such as ground bounce or simultaneous switching noise.
- You want to carefully model the current return paths for signal nets.