X540 Operating Temperature

Hi,

We are interested to use the X540 Twinville Dual Port 10GbE MAC/PHY in our application. The marketing data sheet

Intel® Ethernet Controllers and PHYs

lists the operating temperature at 0-55C. Yet the data sheet

http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/ethernet-x540-datasheet.pdf

on pg 1188 lists a maximum case temperature of Tcase Max = 107C.

Please elaborate on the difference and meaning between these two figures. We need the 0-70C temperature range if we are to use this part.

Thank you.