PLL lock lost at high temperature if not using Wifi

[hacksome]

Hi @ESP

Can I please get some urgent help please re thermal issues.

As per https://github.com/espressif/esp-idf/issues/6697

I am not getting any answers and this is stopping our product from validation.

In short the issue is that the we are using ESP32 as a micro controller (Wifi/BT disabled). During thermal testing the clock drift by a lot and finally the board resets and then it is fine again. This suggests that there is some calibration function going on at start up.
If we enable Wifi we dont see the issue but we cannot enable Wifi as our device does not have RF approvals for Wifi and also no space for the extra RAM and other resources that Wifi needs

Can someone please let us know any API that we can call to keep the board crystals/PLL in tune as the temperature ramps up and down from -40 to +85

Thanks

[ESP_Sprite]

Hm. Crystals can indeed drift a bit with temperature changes, but the 100% your video shows is not really expected. Let me see if I can poke R&D again, perhaps I can find a different answer.