TPS650861: VTT & VREF DDR Power Supply

Part Number:TPS650861

Hello,
For a new design, we plan to use the TPS650861 PMIC to supply a LS1043A processor.

In the TPS650861 datasheet, the "Power Map Example" (Figure 5-2) proposes to supply the VREF & VTT power plans via the "LDO VTT"

I find it very surprising (indeed risky) to feed the VREF and VTT by the same rail power.
The NXP documentation (for the LS1043A CPU) also clearly recommends feeding them with 2 separated rails (to ensure good integrity on the DDR timings).
This recommendation is not limited to LS1043A. It is quite common and that is why the specialized components in the DDR power supply (like the TPS51200) always have separated VTT and VREF outputs.

Would there not be a lack in the management of DDR supplies by this PMIC ?

Thanks,
Samuel