Model Assignments for Signal Integrity Analyzer
once you have the required model, make sure it is in a form compatible with altium designer. (spice3f5, xspice, pspice)
model conversion: converting models into the required format require the user manuals for the source and target.
linking the model to a schematic component:
to create a new simulation-ready device, start by creating a schematic library component for the device using the schematic library editor
to add a link to the simulation model file, add a simulation model link to the component by:
in the models region of the editor’s main design window, click the drop-down arrow and choose simulation from the list of models
OR in the models region of the schematic library panel, click the add button and choose simulation as the model type in the add new model dialog
OR use the model manager dialog (tools > model manager). select the entry for the component, click the drop-down associated with the add button, and choose simulation
after adding the simulation model link you will need to configure the link. you will be taken to the sim model dialog to configure the link to the required simulation model
specifying the model - the model kind and model sub-kind fields need to be set according to the particular model type. the model kind drop-down gives access to a number of model categories in the analog device models built into SPICE. the model sub-kind lists all model types in the corresponding category
many built-in SPICE models do not require a model file. definition is made by setting the required values for model parameters at the component-level. the following is a list of device models that support the use of an associated model file which can contain a variety of parameters used to model advanced characteristics of the device:
Current Source\Piecewise Linear
General\Capacitor(Semiconductor)
General\Diode
General\Resistor(Semiconductor)
Switch\Current-Controlled
Switch\Voltage-Controlled
Transistor\BJT
Transistor\JFET
Transistor\MESFET
Transistor\MOSFET
Transmission Line\Lossy
Transmission Line\Uniform Distributed RC
Voltage Source\Piecewise Linear.
if you are linking a spice3f5 model, select the model kind and sub-kind as per the list above. the spice prefix field will be set automatically
the netlist template
the netlist template allows access to the information that is entered into the xspice netlist for a given component. access it by clicking on the netlist template tab at the bottom of the sim model dialog.
it is read-only for the predefined spice3f5 models. if these do not allow enough control over the information, you can define your own (this is required for certain model types)
set model kind to general and model sub-kind to generic editor
altium designer also offers support for pspice models. these are the pspice models supported:
Capacitor
Resistor
Diode
Inductor
Current-Controlled Switch
Voltage-Controlled Switch
Voltage-Controlled Voltage Source
Voltage-Controlled Current Source
Current-Controlled Voltage Source
Current-Controlled Current Source
Bipolar Junction Transistor (BJT)
Junction Field Effect Transistor (JFET)
Metal Oxide Semiconductor Field Effect Transistor (MOSFET)
select the model kind and sub-kind as you would for the spice3f5 models (with exceptions of resistor, inductor and voltage and current sources – you will need to set the model kind to general and the sub-kind to generic editor to enter the applicable netlist template format)
to link to a digital simcode model
this is a special descriptive language that allows digital devices to be simulated using an extended version of the event-driven xspice
the schematic component is linked to the simcode model by using an intermediate model file (*.mdl) - this calls the simcode description from within its .model line
in the sim model dialog, make sure the model kind is set to general, the sub-kind is set to generic editor and the spice prefix is set to A
you will need to enter the netlist template specific to the digital device being modeled
specifying model name
use the model name field in the sim model dialog to specify the name of the model to which you are linking
specifying model location
use the model location region of the sim model dialog to control where the model is searched for
any - searches all valid model locations for a match]
in file - only searched for a match along all valid model locations
full path - only searched fora a match in the specified file along the specified path
in integrated lib - draws the model from the integrated library used to place the component instance
mapping the ports
after the model file is linked to the schematic component, ensure the pins of the schematic component are correctly mapped to the pins of the model – port map tab of the sim model dialog
the function of each pin in a model can be found in the general form of the model (spice3f5)
for subcircuit models, the manufacturer will typically insert comments for each pin of the model, describing their function
defining component-level parameters
for built in spice3f5, supported pspice and subcircuit model kinds, the available parameters will automatically be listed. when linking models using generic editor, you need to add applicable parameters
for some built-in spice3f5 models, entering a value for a parameter at the component level will override a related parameter defined in a linked model file
if a parameter is specified at the component level for a subcircuit model, the value will override the value defined for it in the linked subcircuit
if a parameter is specified at the component level for a digital device, the value will override the value specified for the parameter in the simcode definition
linking from an external database
altium allows the ability to place components from a company database by creating a database library (*.dblib). placement is carried out from the libraries panel, which after installing the database library acts as a browser into your database
the model and parameter information for a component is stored as part of the record definition for that component in the external database
the referenced schematic component is an empty shell with only a defined symbol. there are no linked models or defined design parameters. when the component is placed, the parameter and model information is created using the corresponding fields in the matched database record
you can add simulation model information to a component record in the external database. after placement on the schematic, the information is used to create the link to the referenced simulation model
adding sim information to an external database table
the database fields can be added to an external database table in order to define the simulation model link - created upon component placement
if the field names are named exactly as indicated, the database field-to-design parameter mapping will be automatically set on the field mappings tab of the dblib file
simulation information must be entered manually into the external database
sim model name
create this in the database to specify the name of the model you wish to use
sim description
create this field if you want to provide a description for the linked model (optional)
sim file
create this field in the database if you want to specify a particular model file in which to find the simulation model specified in the sim model name field:
you can enter an absolute path to a model file - searched and used if found
you can enter a relative path - searched within this file and used if found
you can enter the model filename only - search paths defined as part of the dblib file will be used to locate the first model file that matches the specified name and contains a match for the model specified in the sim model name field
you can leave it blank
sim kind
create this field in the database to specify the parent category for the model being linked to - corresponds to the model kind field on the model kind tab of the sim model dialog
sim sub-kind
create this field in the database to specify the type of model being linked to - corresponds to the model sub-kind field
sim netlist
create this field in the database to enter the netlist template information - **this becomes especially important if you are specifying your own netlist template
sim spice prefix
create this field in the database to specify the spice prefix for the model type you are linking to - corresponds to the spice prefix
sim port map
create this field in the database to specify the mapping of pins from the schematic component to the pins of the linked model - after the component is placed, this information will appear on the port map of the sim model dialog
sim excluded parts
create this in the database if you want to exclude certain parts of a multi-part component from being simulated - corresponds to exclude part from simulation option on the port map tab of the sim model
by default, all parts of a multi-part component are included in a simulation, so you only need to specify the parts you wish to exclude by number
sim parameters
create this field in the database if you want to assign values to simulation parameters for the model - these are parameters that can be defined at the component-level, as opposed to the more advanced parameters that can be included in a model file
a component-level simulation parameter can also be set as a component parameter
by default, a parameter entry in the sim parameters field will be automatically added as a component parameter - if you don’t want this, add an exclamation mark prefix to the parameter name
checking the link
once you placed the component from the database library, double-click on the placed component to access its associated component properties dialog. in the models region of the dialog, double-click on the simulation model entry to access the sim model dialog where you can check:
any linked model file has been located as expected
the remaining simulation information from the database has been added to the dialog as expected
maintaining the link
after placement, the chosen key parameter in the dblib file is used to ensure that the placed component in the schematic retains its link to the corresponding record for that component in the external database - at any stage in the future, changes to parameter and model information in the database can be passed back to the placed component
component design parameters can be updated using either the update parameters from database or update from libraries - both available from → schematic editior’s main tools menu (update of the simulation link information if latter is used)
update process considers the information for the link only. when the model link involves any associated model file (*.mdl, *.ckt), any changes (definitions, parameter values, expressions) required must be made within the file. these changes can be checked from the model file tab of the sim model dialog.
https://techdocs.altium.com/display/AMSE/Linking+a+Simulation+Model+to+a+Schematic+Component