2013-07-07 01:56 PM
The STM32L series does no have a dedicated pin for a battery backup to keep the RTC running when the supply is removed.
What is the recommended way to provide battery backup of the RTC for this series? #rtc #battery-backup-stm32l2013-07-07 02:13 PM
Look at the VBAT pin. It's used to power the backup domain, including RTC and backup SRAM memory. It works with a battery or supercap.
Jack Peacock2013-07-07 02:56 PM
The L series parts are designed to run from a battery, if you expect the device to keep running you're going to need to supply a voltage all the time, either by powering it by a battery with a charger circuit behind it, or split a permanent/temporal supply via some diodes, like a
, or something along those lines. The use of a 32.768 KHz crystal is also recommended, I think you can use other clocks in the L, but all the other STM32 series only have this clock in the backup domain. No VBAT pin on STM32L1xx parts BTW2015-03-26 04:35 AM
Sorry, my mistake.