STM32L471ZGT don't wake-up from standby and shutdown modes at ambient temperatures below -10..15C.

[MV]

Hello.

I want to use STM32L471ZGT to write a rare signal to flash. All the rest of the time it should consume as little as possible. I config RTC for alarm (and then try wakeup), all working

perfectly if ambient temperatures -10C and above. But processor don't wake-up from standby and shutdown modes at ambient temperatures below -10..15C.

LSCO gives a good signal at the same time! RTC counters also working!

It wakes up when it heats up.

Tell me which way to look for the problem, pls.

Thank you in advance.

[AvaTar]

I mean other boards (prototypes) for the same project.

Checking functionality below -10°C sounds like a commercial undertaking, with usually more than one prototype to work on.

[MV]

Yes, i'm testing 4 prototypes.

[waclawek.jan]

@MV​ 

did you come to some conclusion?

Thanks,

JW