We are making a battery powered handheld device, something like a mobile phone or PDA, with user-replaceable battery.
AM335x VDD_RTC need 1.8V power supply, which may be powered by TPS65217C/LDO1 in SLEEP mode; but if user removes battery, RTC is reset.
I wonder what is the recommended way to add a backup battery (3V lithium rechargeable or supercapacitor)?
And if the backup battery discharge to a low level, e.g. user removes the battery for an extended period, put it back and charge the device again, in this case, should I use a separate reset IC to make sure the RTC_PORZ signal is good? or I can reset RTC domain via software or GPIO?
