This is a brief overview of the PulsonixSim Spice Simulation functionality. This is a licensed option and is available from your local sales office.
If you do not have PulsonixSim, you can still generate Spice netlists for some Spice formats, specified by using the Set Netlist Spice Type option from the Simulation menu.
The Simulator
When a simulation is run on a schematic design the PulsonixSim engine is activated. With Probes or Inserted Graphs added to your circuit, successful results will be displayed.
Converting Schematic Designs for Simulation
If you have previously used the older Pulsonix Spice product and intend using the PulsonixSim simulator now, you must convert your designs first before they will simulate. Please refer to the Adjusting Existing Spice Designs page for more information about what needs to be adjusted before you can successfully run simulation in PulsonixSim.
PulsonixSim Simulation Functionality
Simulation Menu
Most of the functions to use for simulation analysis can be found on the Simulation menu and its sub-menus:
Sections in the middle of the menu are used to define Sources, Passive components, Semiconductor components, Miscellaneous items, such as Node Set, Initial conditions, Bias Markers etc, and followed by Probes.
Special Function Keys
As well as options on the Simulation menu, there are two special function keys used for the simulator:
Press F7 to edit the selected component Spice Values, Parameters or Model Name. Its use changes depending on the type of item selected. This is also available on the context menu for a selected component.
Press F9 to Simulate the Schematic Design. With Probes or Inserted Graphs added to your circuit, successful results will be displayed.
Simulation Toolbar
Some of the more commonly used functions are available on the Simulation toolbar:
Preparing the Schematic for Simulation
Using External Spice Models
Spice models that are available on various web sites on the internet can be used with Pulsonix and can be associated with Pulsonix Parts in the library.
Some of the models in the provided libraries will be for devices which may be no longer available. These have not been removed for legacy reasons. Please check device availability before committing to production.
Simulation Parts
Information on Parts is used to indicate what Spice device they represent, the Spice model to use during the simulation, and how to output them to a Spice netlist.
These Parts can represent circuit stimuli (like voltage and current sources), basic Spice devices (analog and digital), sub-circuits, special PulsonixSim functional models and Simulator commands (like Probes and Initial Conditions).
You can set up a Part Spice Type and PulsonixSim information by editing it using the Library Manager and using the Edit Spice button from the Details page. This presents the Define Spice Type dialog to specify the type of device the Part represents.
Libraries are provided for use within Pulsonix containing Parts that have Spice information already set up to help you quickly generate circuits to simulate. These libraries can also be used as a guideline to be referenced when creating your own libraries. These Parts can be found in the PulsonixSim Parts library, and its associated symbol library. It contains special Parts for functional modelling, circuit stimuli, probes etc., along with Parts that reference PulsonixSim simulator models and subcircuits.
Adding Simulator Parts
Add the required Parts from these libraries to your schematic using one of the following methods:
- Add your circuit stimuli components using the Source sub-menu on the Simulation menu. The menu will contain a list of commonly used source devices.
- Add passive components to your design using the Passives sub-menu on the Simulation menu.
- Semiconductor components are available on the Semiconductor sub-menu on the Simulationmenu.
- Add your circuit probe components using the Probes sub-menu on the Simulation menu. The menu will contain a list of probe parts representing commonly used simulation plots. The menu also contains a set of simulator control Parts, Keep parts for controlling what values to store during a simulation.
- Use the Part Browser for a structured tree list of Spice Parts in the Spice library based on their Spice Category. This Spice category can be selected from the Categories list for an instant view of Spice Parts.
- You can also use the normal Insert Component dialog to access the Spice Parts libraries.
Changing Spice Parameters on Parts
Once a Spice Part added, you can alter the Spice information on the component in your circuit by selecting each one and pressing the F7 key, or using the Edit Spice Model/Value command from the Simulation menu. For most devices this will display the Select Model dialog from where you can change the model or subcircuit the component refers to and its model parameters, or the Define Passive Device dialog to change the value of resistors, capacitors, inductors etc.
There are many more special dialogs that respond to the F7 key for different Spice device types, these are listed below.
Functional Model Devices (F7)
See Functional Modelling for more details.
Analog To Digital Converter
Arbitrary Non-Linear Capacitor
Arbitrary Non-Linear Inductor
Arbitrary Non-Linear Resistor
Bus Register
Counter
Digital To Analog Converter
Logic Gate
Laplace Transfer
Non-Linear Transfer
Shift Register
Editing Spice Devices (F7)
Device Value
Digital Initial Condition
Digital Pulse
Ideal Transformer
Model
Parameters
Parameterised Devices
Passive Devices
Potentiometer
Creating the Circuit
Create the circuit using connections and the Spice components ready to be simulated. Insert circuit stimuli by adding voltage and/or current source Parts to the circuit. Add fixed voltage and current probe components to the nets and pins that you wish to plot a simulation graph. You can also add Inserted Graph to display the results of the simulation.
Adding Stimuli and Probes
Connections would be added to the components to create the circuit to be simulated. Insert circuit stimuli by adding voltage and/or current source Parts to the circuit. Add fixed voltage and current probe components to the nets and pins that you wish to plot a simulation graph.
Spice Circuit Design Rules
The following design rules must be observed for the simulation to run correctly. Note that most circuits obey these rules anyway and they do not impose serious limitations on the capability of the simulator.
- There must always be at least one ground symbol on every circuit.
- Every node on the circuit must have a DC path to ground. If you do have a floating node, connect a high value resistor (e.g. 1G ) between it and ground.
- There must not be any zero resistance loops constructed from voltage sources and or inductors. If you do have such loops. insert a low value resistor. It is best to make the resistance as low as is needed to have a negligible effect on your circuit but no lower.
- There should be at least two connections at every pin. Connections cannot be left dangling.
Failure to observe the above usually leads to a “Singular Matrix” error.
Choosing the Analysis Modes
When the circuit is ready, use the Simulation Parameters option from the Simulation menu to choose the analysis mode.
Running Simulation
Starting the Simulation
When all set up, press F9 to run the Simulate Design option. This is also available from the Simulation menu. All pages of the schematic will be collated and the entire schematic simulated.
To simulate only parts of a schematic design, use the Simulate Current Page or Simulate Selected Items options from the Simulation menu. The simulator will be run in synchronous mode, so you cannot use any part of the program while the simulation is running.
Results, Graphs and Random Probing
If the design contains fixed probes, their results will be plotted in a full graph window. You can also use an Inserted Graphs to display the results in an in-design graph.
Alternatively you can use the interactive Random Probe facility from within the schematic editor Simulation menu.
Annotation of Simulation Results
After the simulation has been completed, you can use Bias Annotation to annotate the Schematic with the results of the DC operating point analysis. This requires special markers to be placed on the Schematic. You can instruct Pulsonix to place markers at every node or you can place them manually. The options to perform this can be found on the Bias Annotation sub-menu from the Simulation menu.
Link To ngspice Users Guide
A link is provided here to the ngspice Users Guide. This provides a comprehensive guide to functionality and additional features within the ngspice simulation engine.
Links to Simulation Topics
Creating Spice Devices
Define Spice Type
Functional Modelling
Adding Spice Devices
Part Browser
Show Spice Value
Adding Source Devices
Adding Fixed Probes
Saturable Magnetic Devices
See Saturable Magnetic Components for more details.
Prepare For Simulation
Extra Simulation Data
Import Models
Simulation Parameters
Random Probing
Bias Annotation
See Bias Annotation for more details.
Autoplace Markers
Delete All Markers
Hide Values
Insert Bias Current Marker
Insert Bias Voltage Marker
Probing Current
Update Values
Monte Carlo Simulation
See Monte Carlo Simulation for more details.
Matching Components
Monte Carlo Tolerances
Set Device Tolerance
Set Match Tolerance
Defining Other Spice Formats
See Set Netlist Spice Type for more details.