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Design, Simulate, and Validate Your Circuit With PSpice FAQ

Here are some comprehensive answers to all the questions that were asked in our recent webinar.

PSpice | Simulation and Settings | PSpice Models | Derating | General

PSpice

Does PSpice support DC voltage drop analysis for high current paths?

Yes, you can simulate and analyze the DC voltage drop for high current paths.

How can I connect PSpice to MATLAB?

You can connect them via the PSpice - MATLAB co-simulation flow. PSpice Designer Plus supports the PSpice – MATLAB interface. Setting up of this interface is super simple. All you need is to set your MATLAB installation path under PSpice – MATLAB Setup. This interface will let you generate advance plots using your PSpice simulation result in MATLAB plots and use MATLAB functions in your PSpice simulation and measurements to perform co-simulation using PSpice-MATLAB Simulink. For more information, view this webinar: Combining MathWorks and Simulink with PSpice to Streamline PCB Design.

Does PSpice have a feature that will allow me to identify, the amount of magnetic effect within a circuit? And will I be able to run a thermal simulation of the circuit?

PSpice supports the simulation of non-linear magnetics and fully supports magnetic circuit simulation. Thermal simulation is not available, but you can simulate temperature effect in your circuit analysis. Using PSpice Smoke Analysis you can also simulate the effect of a heatsink on junction temperature of the device under current operating and ambient condition. This enables a user to design a proper heatsink for power semiconductors such as MOSFET, IGBT, BJTs, Diode, etc.

Besides Monte Carlo analysis, does PSpice support any other worst case analysis features?

PSpice supports both Monte Carlo Analysis and worst-case analysis.

Optimizing power transistors for Gate R, Ron, needs to be done many times can it try various parameter changes to get the optimum for you?

Yes, the following three approaches are possible:
a.You can use parametric sweep analysis to sweep different values of the parameter. This enables sweeping of one parameter at a time.
b. Use PSpice Advance Analysis Optimizer to optimize multiple circuits or model parameters to achieve circuit goals.
c.Use PSpice Advance Analysis – Parametric plotter to sweep multiple parameters to explore the solution space and select the appropriate set of circuits or model parameters.

Is PSpice able to run IR Drop analysis?

You can run IR Drop analysis via Analysis Workflows in Allegro X PCB Editor.

Can PSpice handle Verilog FPGA in simulation?

No, PSpice cannot handle Verilog FPGA in simulation.

Can PSpice run millimeter wave (MMW) simulations?

No, PSpice cannot run MMW simulations. However, if you need to run MMW simulations you can use our AWR Microwave Office product suite.

PSpice supports EOS (electrical overstress) does it have any capabilities to analyze ESD (Electro static discharge)?

Yes, you can simulate electrostatic discharge. It needs to be modeled as a form of special sources.

Does PSpice support alternate/additional model formats for mixed mode and electrotechnical simulation?

Yes, it supports alternate/additional model formats both mixed mode and electrotechnical simulations.

Simulation and Settings

How could different simulation be performed (DC, Transient with different parameters), for some complete design model (like Texas Instruments transient model for DC-DC converter)?

You can use parameters (PARAMS) substitution to simulate your circuit under different model parameters.

What about the ITL4 parameter, what is it actually and what are the recommended values for ITL4 so that the simulation does not take an eternity to complete?

The ITL4 parameter is the maximum number of allowed iterations at any given time point in transient analysis. Its default value is 10. If the circuit fails to converge within the default iteration that is set, the step size is reduced, time is backed up, and the calculation is repeated. Increasing the ITL4 will aid in converging the simulation. Ideally the default value should be used and should not be greater than 100.

What is the function of clicking on SKIPBP?

Clicking on SKIPBP, skips the bias point calculation in transient analysis.

What are some common steps or tips to debug a circuit simulation to converge?

Within PSpice there is a feature called Auto Convergence. You can enable this by editing your simulation settings. Go to Simulation Settings > Options > Analog Simulation > Auto Converge. Select the Auto Converge checkbox to enable the setting and click OK.

PSpice Models

For models that are already in the library, can you edit the parameters for models used in your simulation?

Yes, you can override parameters at the schematic level.

Is PSpice compatible with LTspice models?

Yes, most unencrypted SPICE models from LTspice can be simulated as is in PSpice. Encrypted Models and LTspice property devices such as “A” cannot be simulated with any other SPICE simulator including PSpice. However, if there are specific parts you are looking for models for, please let us know. A model editor is available within the product.

Are PSpice models compatible across the platforms like PowerSI and PowerDC too? Along with OrCAD X Capture and Allegro X PCB?

Generic SPICE based models and non-behavioral PSpice models should be compatible with the above-mentioned Cadence platforms.

After you input your model parameters for a device, can OrCAD X automatically find the manufactured device which matches or close to your model parameters?

If these model parameters are device rating, then these can be searched in content providers in the component explorer to get Manufacturer part.

Derating

Are the derating files for the various standards included in the tool installation?

A standard derate is shipped along with no derate option - you can always create custom derating files and use it in Smoke Analysis based on different standards.

For capacitor derating, does PSpice have the capability to check ripple current against maximum ripple current (usually an RMS current value)?

No, currently you cannot stress check for capacitor ripple current using PSpice Smoke Analysis.

Are NASA parts derating standards for space applications available?

You can create your own custom derating files if the derating standards are available to you.

Can I override the derating value for a component at the schematic level, with an attribute, or does it have to be set in the derating file?

Yes, you can apply a d-rate at the global level, or you can apply it at a specific instance level.

General

How do you access the Component Explorer?

Within OrCAD X Capture, select Place > Component from the toolbar menu or use the hot key M.

I want to use a schematic tool for simulation and then later PCB design. How do the applications work between OrCAD X, Allegro X, Presto PCB Editor, and PSpice (what are the differences)? What package(s) should I request from Cadence to perform simulation and PCB design?

PSpice basic is included in all OrCAD X tiers - standard and professional. If you are looking for advanced simulation such as Smoke Analysis, and system simulation you will need OrCAD X Professional Plus that includes full PSpice.

Is there a free version of PSpice available?

You can access a free version of PSpice via the OrCAD X free trialor download a free version of Cadence’s PSpice for TI.

Is there any caveat running PSpice from a remote server rather than running locally? Do the simulations take a longer time to run?

No, it should not have any negative impact. If your remote system has higher compute power and good system specifications, your simulation will run faster.

How is PSpice different from Virtuoso Spectre?

Virtuoso Spectre is used for integrated circuit, and PSpice for PCB simulation, there has been no solution for designers who wanted to analyze IC and PCB components together in the same simulation. However, you can use PSpice models with Spectre. This enables the user to include PCB components in a PSpice format into a Spectre integrated circuit simulation. The solution is based on the approach of using a regular Spectre simulation including the Spectre simulator control statements, but additionally allowing to include user define subcircuits in PSpice format. Be aware that due to the approach described above, this is not a replacement of a PSpice simulation. The solution is available for Spectre and APS simulators.

You are using OrCAD X 23.1 here, does similar functionality exist in OrCAD PSpice Designer Professional 17.4?

Yes, most of the functionality that was shown is available in 17.4. Cadence is continuously improving its solution and adding new features. It strongly encourages users to use latest releases to get maximum benefits. Features such as Live BOM are only available with version 23.1 and up.

I am designing a circuit for a cold area, can I set the surrounding temperature to see what effect it has on the circuit?

Yes, you can set the temperature run to low temperature within the simulation settings GUI via the temperature sweep option.

If I cannot get TC1, TC2 for PSpice model, can I still meaningfully perform temperature analysis in this situation?

You can define absolute temperature for the model using T_ABS. In this, you can define direct values or expressions which models the temperature behavior. With the 23.1 release, you can now model temperature variation as function of time - something no other solution currently provides.

Where can I access the previous webinar recordings on Live BOM and OrCAD X Presto PCB Editor?

a. You can access our previous webinars via this link.

Are the integrated databases for searching parts with 3rd party vendors free of additional costs?

Access to our 3rd party vendors within our Component Explorer is included as part of our solution.

Is Allegro X 22.1 different than OrCAD X PSpice?

Allegro X is our enterprise PCB platform and supports PSpice using either OrCAD X Capture or Allegro X System Capture. 22.1 is the release version - the latest release version is 23.1.

Can I simulate with Allegro X System Capture?

Yes, Allegro X System Capture supports PSpice.

If I have technical questions about PSpice, is there a support page where I can get help?

Yes, you can get support from our community forums here. Create a new post to submit your question(s).

Is there a way to extract the layout parasitics and include them as part of my PSpice simulation?

Yes, there is a way to do that. The Cadence Sigrity solution can be used to extract PCB parasitics and SPICE model for paracitics. These SPICE models can then be stitched back to PSpice circuit (netlist) to perform simulation with layout parasitic.

What are the differences between PSpice for TI and OrCAD X PSpice?

PSpice for TI is our collaborative offering with Texas Instruments (TI), and it offers unlimited or unconstrained simulation for TI devices or any inbuilt model. Using models from external sources such as other semiconductor manufacturer, however, restricts your simulation and plotting to a maximum of up to four waveforms. Whereas OrCAD X PSpice offers you more advanced capabilities in terms of devices such as non-linear magnetics, PSpice Advance Analyses and complete unrestricted simulation independent of the model source.