I have a design that is power sensitive put I also need accurate adc readings. For this reason I'm adding a external prec ref voltage source. I will not be doing measurements all the time and If I shut down the prec ref I can save about 100ua. The only issue is that the Vrefh pin into the micro will be floating. Will this be a issue? The data sheet says unused pins short go to VDD but what happens if I let it float? Since I will not be doing any reading I would think it should not be a issue. It will have a impedance to gnd through the prec ref chip. Would that be good or bad?
Hi Jason,
I think it is ok if it float to ground. Please see this link:
https://community.nxp.com/message/419427?commentID=419427#comment-419427
Regards,
Jing