In our design we are not using the A/D converter. AM335x Schematic Checklist ( http://processors.wiki.ti.com/index.php/AM335x_Schematic_Checklist ) recommends
If ADC is not used...
- Connect all TSC_ADC terminals (VREFP, VREFN, AIN[7:0], VDDA_ADC, and VSSA_ADC) to same ground as all VSS terminals.
Can someone confirm that it is ok to tie VDDA_ADC pin to ground
thanks
bb