I want to use Cerb40 II in a low temperature environment. It looks like LDO is the only part that is limiting its lower bound operating temperature to 0°C. Is it really the case? In other words, if I either replace current LDO with similar one that has extended operating temp range or if I use my own power source instead of USB/5V, I can expect Cerb40 II to be fully operational even at -40°C?
Just use a higher input voltage, and then it’ll stay nice and toasty 
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@ godefroi - Sounds too good to be true
godefroi’s suggestion certainly would help! I know because I’m working the issue from the other direction - overheating of an LM1117 regulator. You just need to be sure you don’t get into thermal shutdown which you can estimate using the LM1117 data sheet, pages 11 & 12. Much would depend on how your board is packaged for thermal considerations.
@ idafez - I will most likely not use LDO at all. What I would like to know is whether there are any other components in Cerb40 II that are not rated to be operational at negative temperatures. I think someone from GHI team, who has BOM for Cerb40 II, could do that check.
You can solve your overheating problem by using SMPS instead of LDO.
@ iamin - You are in luck the LDO we are using, and have been using for a some time, is ZLDO1117G33TA, which goes down to -40C :). The crystal would be the limiting factor as we were using a commercial temp grade, but are now using an industrial temp grade now.
To tell the difference between the crystals, is the commercial one has C01J on the top and is taller, 3.87mm from board to top of the part and the industrial has Z01J and the height is 2.83mm.
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@ Mike - Thanks a lot!
I made a mistake assuming you are using LDO manufactured by TI :-[
@ iamin - No problem.