We want to use a RTC counting with both, VCC and VBATT in our project.
The initial idea was to use the LOCO internal clock to do so, however we've seen that VBAT is doesn't mention this clock to be supplied, only the RTC itself.
Question is simple, is it possible to use the LOCO internal clock to run the RTC with the VBAT supply? Or is it mandatory to use the external Sub-clock oscillator (XCIN and XCOUT pins)?
Thanks!
The external sub-clock oscillator isn't reliable. I gave up and used a DS1338.
Hello,
The VBATT pin supplies power to the following modules:● RTC● Sub-clock oscillator (including XCIN and XCOUT pins)● VBATT Backup Register
So operating RTC from LOCO is not possible while supplying from VBATT.
Sub-clock is also more accurate than LOCO so maybe you should select it for an RTC application.
Clear then. Thanks for the quick answer!