KE04 RTC accuracy

[jun1]

HI.

Thank you for your help.
How accurate is the RTC when a bus clock is used as the RTC clock source?

I looked at the KE04 Sub-Family Data Sheet, but is it ±5% (T = 25 °C, VDD = 5 V) for 37.5 kHz?

jun.

[xiangjun_rong · Accepted solution]

Hi, Jun,

The RTC module is a frequency divider, it's accuracy is totally dependent on the the clock source accuracy. So if you use BUS clock as RTC driving clock source, pls check if you use 37.5 internal IRC or external crystal.

If you use 37.5KHz IRC as RTC clock source, the 37.5KHz IRC after  Factory trimmed is +/-0.5%, I think it is  the RTC accuracy.

Hope it can help you

BR

XiangJun Rong

[jun1]

Thank you for your reply.

37.5 uses internal IRC so factory trimmed value is +/- 0.5%.

OK.

Thank you very much.
have a good day.

Jun.