Anybody have a favorite DC/DC converter IC
I think allowing the voltage to swing that much will really screw up the analog to digital converter readings.
I would just skip the DC/DC converter all together, but I am taking readings from an analog pin
Not if you used the internal voltage reference of 1.1V, that would be independent of supply.
So are there any other problems I might have ...
you will need to condition the input signal to stay between 0 and 1.1V for full resolution analog input.
While you will get the full resolution between 0 and 1.1