[time-nuts] CSAC change in temperature, max is now 40C

[Jim Lux]

The latest rev of the CSAC data sheet (rev H) shows the max 
non-operating temperature to be 40C..
and operating from -10 to +35C

that's a substantial difference from the former version of the sheet 
which presumably had the temperatures from the summary page:
The Quantum SA.45s Chip Scale Atomic Clock (CSAC) is available in the 
following versions:

     Option 001, operates from -10 °C to +70 °C with an output frequency 
of 10 MHz, ADEV = 2.5E-10  (tau = 1 sec)
     Option 002, operates from -40 °C to +85 °C with an output frequency 
of 10 MHz , ADEV = 2.5E-10  (tau=1 sec)
     Option 003, operates from -10 °C to +70 °C with an output frequency 
of 16.384 MHz, ADEV = 2.5E-10  (tau = 1 sec)
     Option 004, operates from -10 °C to +70 °C with an output frequency 
of 10.24 MHz, ADEV = 2.5E-10  (tau = 1 sec)
     Option 006, operates from -10 °C to +70 °C with an output frequency 
of 5 MHz, ADEV = 2.5E-10  (tau = 1 sec)


Rev H appears to be 121014  (12 October or 10 Dec 2014, I'd guess)
http://www.microsemi.com/document-portal/doc_download/133305-quantum-sa-45s-csac


I wonder what happened?  Is it a typo? are they seeing high temperature 
failures?

As a practical matter, a max operating temp of 35 and storage/ship of 40 
would make me nervous about shipping one in midsummer in California..
That brown UPS truck gets pretty toasty warm, and 40C is easily 
achieved, although fairly unusual for "in the shade air temp"

And, of course, makes it useless for outdoor applications of any kind.