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Dead coincell and tamper detection

Question asked by Adrien GRAVOUILLE on Sep 26, 2016
Latest reply on Sep 27, 2016 by igorpadykov

Hi community,  

I'm developing a custom board with the IMX6SL processor, based on EDK.

I will use integrated RTC and tamper detection, which both required an external coincell. I need some help to choose the coincell correctly. My system will run only when it is supplied from a wall USB adapter, so no other battery available.

  1. It seems that's when system is off, it drains up to 250µA from the coincell, which is huge.  A standard rechargeable CR2032 capacity is 40mAh. So, the RTC can work 6 day before being out of power. After that, I will need to plug the board to my wall adapter to make the board working again : is the low voltage of the coincell a problem?
  2. PF0100 integrates a Lithium charger, which current charging is 60µA, so it will take something like 27 days to charge the RTC's coincell?
  3. Finally, is the first case, when battery will be out of power, what will happen with tamper detection when I will bring back the power?


Best regards,