TL750L: Operating Temperature Range

Hi Shinichi, 

(1) Operating Temperature Range is 0 - 125deg, what is the reason 

The operating temperature range of the TL750C is not specified to be 0 ° C or lower.

Could you please tell me what the reason is.

--This device was designed in 1980 and the reason could be from the limitation of the design or process or market positioning. 

(2) What kind of operation is expected when used at -30 ° C?

Does it work improperly?

--I would not recommend using another device against datasheet recommendation. This LDO was not designed and tested for lower than 0C and we don't have any data outside of the recommended temperature range. At lower temperatures, the potential problem could be that the internal circuit fails to start up correctly. To use the device outside of the recommended temperature, the customer would need to run their own validation to confirm if the LDO would satisfy their need. 

Regards, 
Jason Song