use two diodes one to power from vdd and one to power from Batt via 1K to feed RTC. (Or gate)
Picbuster
Just 12 posts up. And on the same page too.
https://forum.allaboutcircuits.com/threads/batttery-backup-of-the-rtcc.141621/#post-1195072
use two diodes one to power from vdd and one to power from Batt via 1K to feed RTC. (Or gate)
Picbuster