Hi, we are using M41T83RMY6F for RTC function on our board. However, we have seen issue at -25⁰C and below i.e. -40⁰C. We executed a test where our board was dwelled at -25C for 4 hours and in one test we executed test at -40⁰C for 96 hours. In both cases we noticed a lag of nearly 2 minutes with respect to Universal time.
Before test the clock was in sync with UST however post test completion we noticed lag. Can you please suggest what could be causing this issue? We do notice in hardware we have the series diode, resistor and capacitor with VBAT which may not be needed by this chip however can't directly relate it to cold test. Kindly suggest what else we can check from software/hardware perspective.
