The accurate of integrated RTC in STM32F103C8T6

[Nguyen Bao]

Hello everybody,

I want to design an application with RTC, I was very impressive with the accurate of DS3231 with small deviation for long time working.

But the chip DS3231 is quite large meanwhile RTC is already integrated in STM32 also. I just want to know about the accurate of this integrated RTC, is it good enough to replace current timer chip like DS1307 or DS3231 ?

Thank you in advance !

Have a nice day :smiling_face_with_smiling_eyes: !

[waclawek.jan]

RTC precision is given by the 32.768kHz crystal's precision and its surrounding circuitry. Read AN2867.

The 'F1 RTC is simpler than RTC in other STM32 families, consisting primarily of only one counter. IIRC "libraries" for the 'F1 don't handle very well the date (I don't use Cube nor any other "library").

JW

[Nguyen Bao]

Yeah !

I wondered this question after reading this article :https://blog.dan.drown.org/rtc-comparison/

PCF2129 also has integrated 32.768 crystal and temperature compensation crystal, but the deviation is quite significant different.

But now i had the answer after reading AN2867, via checking PPM.

Thank you a lot ! :beaming_face_with_smiling_eyes: