LPC Microcontrollersのトピック KE04 RTC accuracy

KE04 RTC accuracy

jun1 — Thu, 16 Jul 2020 01:20:30 GMT

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.

Re: KE04 RTC accuracy

xiangjun_rong — Thu, 16 Jul 2020 04:04:21 GMT

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

XiangJun Rong

Re: KE04 RTC accuracy

jun1 — Thu, 16 Jul 2020 04:14:15 GMT

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.