as DLPA3000 spec & SLMA002 define:
1. Thermal pad:12.00x12.00;
2. Exposed thermal pad:6.00x6.00;
3. VIA 7x7;
Detail footprint as attachment;
But to my opinion, exposed thermal pad 12.00x12.00 has good thermal dissipation than 6.0x6.0;
The reason for TI suggestion to Choosing exposed thermal pad 6.0x6.0 is ....??