What IBIS models can be used for the Si59x oscillators?
The Si59x series of crystal oscillators (Si590, Si591, Si595, Si597, Si598, and Si599) use the same I/O buffers as the Si53x, Si55x, and Si57x devices. The most significant difference between these devices is the internal crystal. The Si53x, Si55x, and Si57x devices all use a 114.285 MHz 3rd overtone crystal. By contrast, the Si59x series uses a relatively cheaper fundamental mode 39.17 MHz crystal.
Since the I/O buffers are the same, IBIS simulation can be done using Si53x, Si55x, and Si57x IBIS file counterparts. For example, an Si590 with output format 3.3V LVPECL can be simulated using the Si530 3.3V LVPECL IBIS file, available online as si530_3v3_lvpecl.ibs.