AHA! that was the info I was after, thanks again skimask.

So, after reading the datasheet I see that I can set the internal Vref for this purpose, but I dont understand something, from the datasheet:


VRR = 1 (Low Range): CVREF = (VR3:VR0/24) x VDD
VRR = 0 (High Range): CVREF = (VDD/4) + (VR3:VR0 X VDD/32)

So in my example, if I set VR3:0 say at 1101 I get these values:

VRR=1 2.167v
VRR=0 2.625v

or if I use VR3:0 at 1001 I get these

VRR=1 1.5v
VRR=0 2.125v


So what should I use, VRR=1 or 0 ?