IBIS Designer

R2026b

Create IBIS model files from SPICE simulation data or electrical parameters

Since R2026b

Description

The IBIS Designer app creates IBIS (I/O Buffer Information Specification) model files from either SPICE simulation data or electrical parameters. The app supports two workflows:

SPICE Simulation — Convert SPICE simulation outputs (such as IV sweeps, transient waveforms, AC admittance) into a complete IBIS model. This is the primary workflow for creating models from silicon characterization data.
Parameterized Model — Generate an IBIS model from a small set of electrical parameters (such as driver impedance, rise/fall time, die capacitance) without requiring SPICE simulation. This workflow is mostly used for early-stage design exploration or creating representative models from datasheet specifications.

At the end of both workflows, the app produces a standards-compliant .ibs file that you can used with any IBIS-compatible signal integrity simulator such as Signal Integrity Toolbox™.

Open the IBIS Designer App

MATLAB^® command prompt: Enter ibisDesigner.

Examples

Programmatic Use

ibisDesigner opens a new session of the IBIS Designer app.

ibisDesigner(SessionFile) loads a saved session file.

More About

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Supported Model Types

IBIS Designer supports all 14 IBIS v8.0 buffer model types, organized into three behavioral categories:

Input Category

This category includes the models that receive signals. They produce ground clamp and power clamp IV curves and die capacitance (C_comp) but does not produce any pull-up or pull-down IV or VT waveforms.

Model Type	Description
`Input`	Standard CMOS input buffer
`Input_ECL`	ECL-level input buffer

Output Category

This category includes the models that drive signals. They produce pull-up and pull-down IV curves, rising and falling VT curves, ramp data, and die capacitance.

Model Type	Description
`Output`	Standard push-pull output driver
`Output_ECL`	ECL-level output driver
`Open_drain`	Output with no pull-up (open-drain/NMOS only)
`Open_sink`	Output with no pull-up (current-sink
`Open_source`	Output with no pull-down (current-source)

I/O Category

This category includes bidirectional models that combine the input and output behavior. They produce all curve types: pull-down and pull-up IV, ground and power clamp IV, VT waveforms, ramp, and die capacitance.

Model Type	Description
`I/O`	Standard bidirectional I/O buffer
`I/O_ECL`	ECL-level bidirectional buffer
`3-state`	Tri-state output (I/O without simultaneous input)
`3-state_ECL`	ECL-level tri-state
`I/O_open_drain`	Bidirectional with no pull-up
`I/O_open_sink`	Bidirectional current-sink (no pull-up)
`I/O_open_source`	Bidirectional current-source (no pull-down)

You can configure all model types as differential. When you enable the differential mode, the IBIS output includes a [Diff Pin] section specifying the pin pairing and differential voltage.

I/O and Input model types support on-die termination (ODT). When you enable ODT:

Driver IV extraction uses raw currents (no off-state subtraction).
Clamp curves are emitted as a [Submodel] section with Submodel_type Dynamic_clamp and an [Add Submodel] reference in the model

Output Summary

The app generates IBIS models as .ibs file that contains these sections:

Section	Input	Output	I/O
`Pulldown`		×	×
`Pullup`		×	×
`GND Clamp`	×		×
`POWER Clamp`	×		×
`Rising Waveform`		×	×
`Falling Waveform`		×	×
`Ramp`		×	×
`C_comp`	×	×	×
`Vinl/Vinh`	×		×
`Vmeas/Vred`		×	×
`[Diff Pin]`	`if diff`	`if diff`	`if diff`
`[Submodel]`	`if ODT`		`if ODT`

Version History

Introduced in R2026b