STM32WL Maximum storage temperature

[Terry Barnaby]

I have an unusual question. The storage temperature range for an STM32WL is stated as: -65 to +150 °C.

We are looking at doing some particular tests at high temperatures for radiation exposure recovery, so some questions if anyone knows:

1. If we put the chips in an oven at 140 °C, powered off, for 6 months is there a likely hood of FLASH data loss ?

2. If the FLASH does lose data, I assume some factory settings could also be lost ?

3. Is it possible to reprogram the factory settings and the internal ROM code if this gets messed up ?

4. Would the STM32 still be accessible via the SWD interface even if the internal settings/FLASH is messed up ?

[STTwo-32]

Hello @Terry Barnaby 

To answer those questions and have complete guidance on that. I suggest you take contact with our Sales and marketing Teams or contact one of our FAEs. They may can provide you with such details.

Best Regards.

STTwo-32

[Terry Barnaby]

Ok, I can't see a way to contact ST Sales and Marketing on the ST website, so I will open a support ticket.

[Terry Barnaby]

Ok, I am not getting any useful answers from the ST support via tickets. Just getting answers like: "The storage is up to 150°C so no problem for data retention when the product is stored up to the tolerated temperature".

Obviously this is not useful as all FLASH will lose its contents after a time and much much quicker at higher temperatures.

1. Does anyone have any information on how long the STM32WL chips will likely retain their FLASH contents at 140C ?

2. Does anyone know what factory set FLASH data may be lost and if there would be a way of re-writing this if it does ?

[STTwo-32]

Hello, 

I've escalated this request internally (under internal ticket number 191753) and I will be back to you as soon as I have an answer. 

Best Regards.

STTwo-32

[jgoril2]

Hi.

Any news on this topic? I have similar problem on STM32G473CCU6TR. It seems that pre-programmed device loses data during the soldering (assembly on PCB).

[Terry Barnaby]

Still no answers from ST despite a field engineer raising a ticket and checking the status frequently.

We have just started our own testing here. We now have an oven and are performing accelerated FLASH data loss tests at 170C. Our boards have test firmware to validate the FLASH (and other aspects on our boards). We will check them once a day to see when the first FLASH data loss is noticed.