Thermal design is critical for all board designs and must also work for the mechanical design of the application. Thermal design must ensure the application is kept within its thermal limits. Xilinx provides thermal models for all devices that can be used with Siemens Flotherm and Ansys IcePack.
You can obtain the Theta Ja of a system through a thermal simulation, which ensures a more accurate power estimation and power delivery solution. Versal devices are available in lidless packaging, providing an optimal thermal solution but requiring that existing lidded designs are targeted to the lidless packaging. Versal devices allow a temperature excursion to 110°C for 3% of lifetime, giving additional thermal margin and simplifying thermal design.
You can refine the initial power estimation with the results of the thermal simulation to get a more accurate estimation of junction temperature. Enter the maximum ambient temperature for the application with the Theta Ja, which provides the worst case static power and ensures the power delivery solution is designed correctly.
For more information, see the Thermal page on the Xilinx website and Extending the Thermal Solution by Utilizing Excursion Temperatures (WP517).