I use the ADUC824 and ADUC834 for measuring a sensors bridge voltage. After AD-Conversion the MCU removes an offset value and multiplies the ADC-value by a gain factor. Both numbers (offset and gain) are stored in the EEPROM during a calibration routine.
In the application the whole system is powered off for 10 minutes and then powered on for 1 minute to measure the voltage.
Now my problem is, that after 10 or more days some of the ADUCs seem to lose their calibration values. I wrote a routine to read out the EEPROM and I can see, that there are corrupt bytes in the EEPROM.
Do you have any idea / hint why this behaviour occurs? The only idea I have is that there may be little spikes on the supply voltage line. I don't use a RESET-circuit, RESET line is pulled down to GND (R = 10kOhm).
Thanks for your advice in advance!