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Contents
How to Use This Online Manual
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How to print this online manual
How to Use This Online Manual Welcome to OrCAD
Welcome to OrCAD
Overview
Typographical conventions
How to Use This Online Manual Overview
Command syntax formats
Notation Examples Description
Numeric value conventions
Numeric expression conventions
Function * Meaning Comments
If x is greater than max xn, then the value is the yn associated with the largest xn. If x is less than the smallest xn, then the value yn is associated with the smallest xn.
How to Use This Online Manual Overview Expressions can contain the standard operators as shown in the following table
Operators Meaning
Command line options for OrCAD applications
Command files
Creating and editing command files
How to Use This Online Manual Command line options for OrCAD applications
Log files
Editing log files
How to Use This Online Manual Command line options for OrCAD applications To run the command log
Simulation command line specification format
Simulation command line options
Specifying simulation command line options
Commands
Command reference
Commands Command reference for PSpice and PSpice A/D
Arguments and options
Parameter Description Description
Commands .ALIASES, .ENDALIASES (aliases and endaliases)
ALIASES, . ENDALIASES
Purpose The .DC command performs a linear, logarithmic, or nested DC sweep analysis in the circuit.
Parameter Description Meaning
Commands .DC (DC analysis)
Linear sweep
Logarithmic sweep
Nested sweep
Parameter Description Meaning Source A name of an independent
Commands .DISTRIBUTION (user-defined distribution)
Deriving updated parameter values
Usage example
Commands .END (end of circuit)
The .EXTERNAL external port statement applies only to nodes that have digital devices attached to them. Comments When a node is included in an .EXTERNAL statement it is identified as a primary observation point.
Commands .FOUR (Fourier analysis)
See How to Use this Online Guide for a list of valid terms. FUNC arguments cannot be node names. Creating a file of commonly used .FUNC definitions and accessing them using the .INC command near the beginning of the circuit file can be helpful. FUNC commands can also be defined in subroutines.
Commands .IC (initial bias point condition)
Comments Including a file is the same as bringing the file's text to the circuit file. Included file comments are then treated as if they were found in the parent file.
Commands .LIB (library file)
Arguments and options [file_name]
Notes Typically, the bias point file is produced by a previous circuit simulation using the .SAVEBIAS (save bias point to file) command. The bias point file is a text file that contains one or more comments lines and a .
Commands .MC (Monte Carlo analysis)
Function Definition
YMAX RANGE(*,.5) YMAX is evaluated for values of the sweep variable (eg time and frequency) of .5 or less. MAX RANGE(-1,*) The maximum of the output variable exists for values of the sweep variable of -1 or more.
Commands .MC (Monte Carlo analysis) Comments The first run uses nominal values of all components. Subsequent runs use variations on model
The model types for the current model and the AKO (A Kind Of) reference model must be the same. There can be more than one model of the same type in a circuit, although they must have different names.
Commands .MODEL (model definition)
Model type Instance name Type of device
The LOT tolerance requires that all units referencing the same model use the same model parameter adjustments. This makes it possible to correlate deviations between parameters in the same model, as well as between models.
Distribution
The generators for DEV and LOT tolerances are different: there are ten generators for DEV tracking and ten generators for LOT tracking. The default distribution can be set using the DISTRIBUTION parameter in the .OPTIONS (analysis options) command.
Parameters for setting temperature
Model parameters for device temperature
Referencing device
Special considerations
Commands .NODESET (set approximate node voltage for bias point)
Integer indicating how often the detailed noise analysis data is written to the output file. The gain from the input source to the output voltage, the total output noise and the equivalent input noise are all calculated.
Commands .NOISE (noise analysis) Every nth frequency, where n is the print interval, a detailed table is printed showing the
Without the .OP command, the only information about the bias point in the output is a list of node voltages, voltage source currents, and total power dissipation. Using an .OP command can cause small-signal (linearized) parameters for all the nonlinear controlled sources and all semiconductor devices to be printed in the output file.
Commands .OPTIONS (analysis options)
Flag options
Option with a name as its value
Numerical options with their default values
These options are available for modification in PSpice, but it is recommended to use the program's defaults.
Numerical options with their default values (continued)
PSpice A/D digital simulation condition messages
Message type Meaning
The reporting of the suppressed error hazard indicates that there may be a problem with either the stimulus or the path delay configuration of the circuit. If the effects of any of the other logical hazard messages mentioned in the output file are able to propagate to either an EXTERNAL port or to any storage device in the circuit, they are marked as PERSISTENT DANGERS.
Commands .PARAM (parameter)
Predefined parameter Meaning
See .PROBE for output variable syntax. lt;lower limit value>,
Commands .PLOT (plot) If the different output variables differ considerably in their output ranges, then the plot is given
Purpose The .PRINT command allows output of DC, AC, noise, and transient analysis results in the form of tables, known as print tables in the output file. The first item to print is a node voltage, the second item is the voltage across a resistor, and the third item to print is another node voltage, even though the second and third items both start with the letter R.
Arguments and options [/DGTLCHG]
Commands .PROBE (Probe)
DC Sweep and transient analysis output variables
Multiple-terminal devices
Character ID Two-terminal device
Three & four-terminal device type Terminal abbreviation
Three & four-terminal device type Terminal abbreviation
AC analysis
Suffix Meaning of output variables
Noise analysis
Output variable Meaning of output variables for noise analysis
Commands .SAVEBIAS (save bias point to file)
Usage examples
Commands .SAVEBIAS (save bias point to file) following analysis types: .STEP (parametric analysis), .DC (DC analysis),
Commands .SAVEBIAS (save the bias point to a file) of the following analysis types: .STEP (parametric analysis), .DC (DC analysis), . However, if
Commands .STEP (parametric analysis)
Arguments and options Sweep type
Sweep types Meaning
Sweep Variable
The RVAL parameter is global and PARAM is the keyword used by the .STEP command when using a global parameter. Therefore, if the line value of the resistor is set to one ohm, the final resistance value will be 1 R or R.
Commands .STIMULUS (stimulus)
SUBCKT (subcircuit)
ENDS (end subcircuit)
Whenever a subnet is used by device X (an instance of a subnet), the entire netlist in the definition replaces device X. Statements calling a subnet must contain the same number of nodes as in its definition.
Commands .TEMP (temperature)
Text expressions Definition enclosed in “ ” text constants
Commands .TF (transfer)
Purpose The .TRAN command causes a transient analysis to be performed on the circuit and specifies the time period for the analysis.
Arguments and options [/OP]
Commands .TRAN (Transient Analysis) Comments Transient Analysis calculates the behavior of a circuit over time, always starting at TIME=0.
Commands .TRAN (transient analysis) Comments The transient analysis calculates the circuit’s behavior over time, always starting at TIME=0
The radix of the values for the specified nodes is defined if
Commands .VECTOR (digital output)
If during the simulation the voltage at node three exceeds four volts, the simulation will stop. If the simulation is allowed to continue and node three continues to increase in value, then the simulation is not interrupted.
Commands .WCASE (sensitivity/worst-case analysis)
Sensitivity and worst cases are performed using variations of the model parameters as defined by the DEV and LOT tolerances for each .MODEL (model definition) parameter (see page 1-52 for details on DEV and LOT tolerances). You can run .MC or .WCASE for a circuit, but not both in the same circuit.
Commands * (comment)
Commands + (line continuation)
Differences between PSpice and Berkeley SPICE2
Commands Differences between PSpice and Berkeley SPICE2
Analog devices
These analog devices contain all of the standard circuit components not normally considered part of the two-state (binary) devices found in the digital devices. The Device type summary table lists all analog device primitives supported by PSpice A/D.
Device types
Analog device summary
Device type Letter Declaration format
Diode D D
Analog device summary (continued)
Stimulus units* U STIM U
GaAsFET
Arguments and options [area value]
Analog devices B
Capture parts
Setting operating temperature
Model parameters
GaAsFET model parameters for all levels
GaAsFET model parameters specific to model levels
Model parameter Description Units Default
GaAsFET model parameters specific to model levels (continued)
Auxiliary model parameters BTRK, DVT, and DVTT
GaAsFET equations
GaAsFET equations for DC current: all levels
GaAsFET equations for DC current: specific to model levels
Idrain Normal mode: Vds > 0
Idrain Normal mode: Vds > 0
Idrain Normal mode: Vds > 0
Inverted mode: Vds < 0
Idrain Normal mode: Vds > 0
Inverted mode: Vds < 0 Idrain =
Idrain Normal mode: Vds > 0
For cutoff region
GaAsFET equations for capacitance
If the source and drain potentials swap, the model inverts over a range set by α. The model maintains a linear relationship between gate-source capacitance and gate bias in the range Vgs > FC · VBI.
GaAsFET equations for temperature effect
GaAsFET equations for noise
Capacitor
Analog devices C
Breakout parts
Part name Model
Device type
Part
Capacitor model parameters
Capacitor equations
Capacitor value formula
Capacitor equation for noise
Model parameters *
Analog devices D
Diode
The following table lists the set of diode decoupling parts designed for customizing model parameters for simulation. The operating temperature can be set to be different from the global circuit temperature by defining one of the model parameters: T_ABS, T_REL_GLOBAL or T_REL_LOCAL.
Part name Model type Property Property description DBREAK
These are useful for setting up Monte Carlo and worst case analyzes with device and/or lot tolerances specified for individual model parameters.
Diode model parameters
Diode equations
Diode equations for DC current
Diode equations for capacitance
Diode equations for noise
Diode equations for temperature effects
Voltage-controlled voltage source Voltage-controlled current source
Analog devices E/G Arguments and options
Basic SPICE polynomial expressions (POLY)
Basic controlled source properties
Part name Property Description E
When defining a higher dimension current-controlled source part, the TEMPLATE property must allow for the same number of current-sensing voltage sources (equal to the dimension value). The VH1 and VH2 fragments after the \n characters represent the device declarations for the two current-sense voltage sources required by this part.
Implementation examples
The above is written for a voltage-controlled voltage source, but the form is the same for the other sources. The POLY entity types shown in Basic Controlled Source Properties are defined with a dimension of one, meaning that there is only one controlling source.
Analog devices F/H
Current-controlled current source Current-controlled voltage source
Arguments and options (+) and (-)
Independent current source & stimulus Independent voltage source & stimulus
Analog devices I/V Arguments and options
Independent current source & stimulus (EXP)
Waveform parameters
Independent current source and stimulus exponential waveform formulas
Time period Value 0 to <td1> i1
Analog devices I/V
Independent current source & stimulus (PULSE)
Independent current source and stimulus pulse waveform formulas
Independent current source & stimulus (PWL)
Parameter *
Only numbers (with units attached) can appear in the file; expressions for
Independent current source & stimulus (SFFM)
Parameters Description Units Default
Independent current source & stimulus (SIN)
Independent current source and stimulus sinusoidal waveform formulas
Time period Value
Analog devices J
Junction FET
The following table lists the set of JFET breakout parts designed to adjust model parameters for simulation.
Part name Model type Property Property description
VTO < 0 means the device is a depletion-mode JFET (for both N-channel and P-channel) and VTO > 0 means the device is an enhancement-mode JFET.
Model parameters *
JFET equations
JFET equations for DC current
JFET equations for capacitance
JFET equations for DC current (continued)
JFET equations for temperature effects
JFET equations for noise
Inductor coupling (and magnetic core)
Transmission line coupling
Description
Analog devices K
Inductor coupling
These values are not available for .PRINT or .PLOT output. winding inductances in Henries COUPLING mutual coupling coefficient. K_LINEAR Ln Transformer Inductor Reference Designator. XFRM_JOLINEAR transformer L1_TURNS L2_TURNS. number of turns in each winding COUPLING mutual coupling coefficient. must be between 0 and 1) Nonlinear CORE model name MODEL. The model must refer to a CORE model such as those contained in MAGNETIC.LIB or other user-defined models.
Device type Part
The point convention for coupling is related to the direction in which the inductors are connected. For linear coupling L1 and at least one other Li must have values; the rest can be left blank.
For example, when the inductor part L is installed without rotation, the dotted pin is left.
Inductor coupling: Jiles-Atherton model
Inductor coupling model parameters
Reversible wall motion comes from bending in the domain walls, especially when pinned at a dislocation due to the magnetic potential (that is, the magnetization is not the anhysterical value).
Including air-gap effects in the inductor coupling model
Getting core inductor coupling model values
The model used to simulate this system is based on the approach described by Tripathi and Rettig in Reference [1] of References and is extended for lines with losses by Roychowdhury and Pederson in Reference [2]. The approach involves computing the system propagation modes by extracting the eigenvalues and eigenvectors of the matrix product [L][C].
Lossy lines
1] Tripathi and Rettig, "A SPICE model for multiple coupled microstrips and other transmission lines", IEEE MTT-S Internal Microwave Symposium Digest, 1985.
Inductor
Analog devices L
For non-stock passive and semiconductor devices, Capture provides a set of breakout parts designed to customize model parameters for simulation. Basic breakout part names consist of the inherent PSpice A/D device letter plus the suffix BREAK.
For example, the DBREAK part refers to the DBREAK model, which is derived from the intrinsic PSpice A/D D model (.MODEL DBREAK D). For breakout part LBREAK, the effective value is calculated from a formula that is a function of the specified VALUE property.
Inductor equations
Inductance value formula
Inductor equation for noise
Inductor model parameters
MOSFET
Arguments and options L and W
Analog devices M AD and AS
A series device multiplier (default = 1.0) for the level 5 model only, which simulates an approximation of the effect of multiple devices in series. Comments The simulator provides six MOSFET device models which differ in the formulation of the I-V characteristic.
Analog devices M
MOSFET model parameters
Model levels 1, 2, and 3
Model level 4
Analog devices M example, VFB is a basic parameter using units of volts, and LVFB and WVFB also exist and
Model level 5 (EKV version 2.6)
Do not apply the LOT specification, which is a measure of the ability of the process to control the absolute value of a model parameter, to AVTO, AKP and AGAMMA, as it would be redundant with the LOT specification for VTO, KP, and GAMMA. These parameters are only used if COX, GAMMA and/or PHI, VTO, KP and UCRIT are not specified respectively.
Model level 6 (BSIM3 version 2.0)
Model level 7 (BSIM3 version 3.1)
BSIM3 version 3.1 retains the extensive built-in dimensional and processing parameter dependencies of BSIM3 version 2.
Analog devices M If GAMMA2 is not given, then
MOSFET model parameters (continued)
DC parameters
- E18 (PMOS)
- E3 (PMOS)
- E-12 (PMOS) level 7: NQS parameter
W and L parameters
MOSFET Equations
MOSFET equations for DC current
MOSFET equations for capacitance
