My AVR is connected to 3 pressure sensors on the Analog inputs. the sensors report 0 - 5 volts. The AVR is powered by a LDO 5v regulator and the sensors are powered by their own 5 volt regulator and both regulators are supplied by the same 12 volt supply.
For best accuracy then I Connect the AREF pin to the same 5v the regulators are connected to.
What else can I do to reduce or eliminate any voltage drift between the 2 regulatos?