My customer used NHS3100 internal RTC with 32kHz FRO clock. There's considerable deviation for the RTC.
At room temperature, the deviation is less than 10s per two days;
If placed two boards in the fridge, where the ambient temp is about -10~-20℃, the deviation between the two boards is about 20min per day. While with sw calibration, the deviation could be reduced to several minutes.
Customer questions are:
1. Do we have the accuracy characteristic of the internal 32kHz FRO clock/ RTC?
2. Do we have ANs or suggestions to improve the RTC accuracy of wide circumstance temp range?