IBIS stands for input/output buffer information specification. It represents the characteristics or behavior of the digital pins of a device that IC vendors provide to their customers for use in high-speed design simulations. These models mimic the device’s I/O behavior using parameters specified by the IBIS Open Forum, an industry organization that manages and updates the specifications and standards for IBIS models.
IBIS models use an ASCII text file format by means of tabulated voltage-current and voltage-time information. They don’t contain proprietary data because the IC schematic design information—such as transistor sizes, parameters of the device model used in the design of the buffer schematic, and circuitry—aren’t revealed in the model. Furthermore, IBIS models are supported by most EDA vendors and can be run in a majority of industry-wide platforms.