TMS320F2812: Need Thermal information for the GBBA package

Part Number: TMS320F2812

Hi, 

the F2812 uBGA package is now moving to the GBBA.

Designer needs help with the thermal resistance of the GBB package

Where can we find this information?

In the datasheet is not indicated for GBB package, only for the old package (ZHHA)

https://www.ti.com/lit/ds/symlink/tms320f2812.pdf

thanks

Olivier