Google couldn't find anything, so figured I put this info online . . .
The Sharp IR datasheets are unclear, saying Vcc should be 4.5V to 5.5V, but also said max Vcc ratings can be from -0.3V to 7V . . .
I just ran an experiment to see if the Sharp IR can run at 3.3V and it does.
I used the 2Y0A21 Sharp IR using 3.3V from the Axon. I got an 8 bit ADC range of about 65 far away to 125 close up.
Now if only Sharp IR released output data for 3.3V and not just 5V . . .