M41T93ZMY6F RTC resets at negative temperature

[ANell.1]

1. Can you tell us why this RTC reset happens only in the negative temperature?

2.Also,during battery powered ON condition,does the leakage current Loads through RTC supply(VCC) causing a voltage Dip in the battery voltage?

 

Dear Sir/madam,

We are using Serial RTC chip (M41T93ZMY6F) in one of our application.

In the datasheet,it is given as the RTC chip can be operated in the range of -40 deg C to +85 deg C.

During Low temperature (-10 deg C), vacuum condition (5*10^-5 bar), we have seen RTC reset issue. But it has recovered in Positive temperature(+45 deg C) in vacuum condition.

RTC reset will happen only when battery voltage is <1.8V .

We are using BR1632A/FAN battery for RTC Back-up supply . Referring to the battery's datasheet,it is mentioned that the operating voltage will be 2.7V(approx)@ -10 deg C.

1. Can you tell us why this RTC reset happens only in the negative temperature?
2. Also,during battery powered ON condition,does the leakage current Loads through RTC supply(VCC) causing a voltage Dip in the battery voltage?

 

[waclawek.jan]

If a 3V cell's output voltage drops to 1.8V, there's probably significant current drawn from it. I don't think it's temperature-specific. Measure the current and if high, find you why.

JW