SPISim_IBIS: A free web app for simulating IBIS using free simulators

SPISim_IBIS: A free web app for simulating IBIS using free simulators

Application Screenshot:


SPISim_IBIS is a browser based web app. It allows user to convert an IBIS model to corresponding spice sub-circuit then simulate with free circuit simulator such as LTSpice, NGSpice or SSolver. Simulation output is also in open format such as Berkeley .raw format which can be viewed with free tool such as SPILite or KJWave. There are quite several free spice-based simulators available on line. However, they are either transistor centric (thus have various BSim models) or are vendor's specific products focused (such as VR for LTSpice, now Analog Device). While most of them also include some supports for interconnect such as two port S-parameters, Lossy/Lossless transmission lines etc.. , almost none or very rare of them support IBIS models. That's where this tool fills the gaps. By converting IBIS to corresponding .subckt file, user can then assemble a system and perform preliminary studies or analysis without any upfront cost. For comparison, a system SI tool usually costs tens of thousands US dollars and may cause EDA vendors locked-in. This tool will never expire. It patches itself and run directly from the browser. While the converted models will use IBIS's "ramp" data only, you can always unlock or request for "IV Table" based model at a very low price!. See "Unlock" tab for details. Please see the following two posts regarding design concepts behind SPISim_IBIS:
To use SPISim_IBIS web app: Step:
  1. Select the free simulator to be used. Converted model will be simulator dependent.
  2. Browse or enter the model file to be generated. Suggested extension is .cir or .lib. This generated file will contain .subckt definitions for those converted IBIS model and corners.
  3. Browse to select the IBIS model file.
  4. After step 3 is completed, all its IBIS model will be available here for further selection. Select the model to be converted here. If parsing is not successful, please see "Support" tab for further info.
  5. Select the corner (typ, min or max) to be converted
  6. Click "Add to list" so this specific file/model/corner combination will be added
  7. Make sure at least one setup has been added. User may repeat from step 3 to add other file/model/corner combinations.
  8. Click "OK" and the model will be converted
Two files will be generated:
  • The specified model file (.cir/.lib) will contain .subckt definition of the converted IBIS model
  • The .spc file is a testbench for you to test drive the generated model using specified free simulator.
Output waveform will be in .raw format mostly, which is an open format and can be viewed with free SPILite or like.
This free web app converts IBIS model to Spice .subcircuit based on its ramp data, which define 20% ~ 80% of the rising or falling transition slew rate linearly. To obtain more accurate representation of the IBIS model, the I/V and V/T waveform table info. should be used instead. The "Waveform data" based conversion is not enabled in this free web apps.

SPISim provides conversion service based on the IBIS's waveform data for $310.00 per model, all Typ/Min/Max corners included. Discount available for multiple models to be processed at the same time. Credit card payment accepted via PayPal.

This function, along with other IBIS modeling and tuning flow, is also available in the SPISim Modeling Suite.

Support for SPISim's free web apps is on best-effort basis.

For SPISim_IBIS, the IBIS to Spice conversion tool, the most probable cause of failure is the parsing of user provided .ibs file. When this happens, tool will not index existing ibis models for user to select for conversion.

If possible, please send the .ibs file to the SPISim support. When NDA is of a concern, please create a mock-up .ibs model will can reproduce the issue.

Free simulators' convergence or usage is beyond our support. Please contact respective companies or organization, such as Analog Device for LTSpice and NGSpice user's forum for further info.

SPISim's support team can be reached via support@spisim.com

Run Application:

  • First time user? Read how to launch SPISim web apps [HERE].
  • Launch SPISim_IBIS from the web browser now:

More IBIS Capabilities:

  • For more IBIS modeling capabilities, check-out SPISimPro