[time-nuts] Thunderbolt temperature measuring

[Didier Juges]

The SMT package was soldered directly to the PWB while I understand the DIP
package is up in the air, that will affect the thermal time constant between
the PWB and the chip quite a bit. I think I would glue the DIP on the PWB
dead-bug style myself. That would get you close to the original
configuration.

Didier 

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Mark Sims
> Sent: Sunday, July 26, 2009 5:37 PM
> To: time-nuts at febo.com
> Subject: [time-nuts] Thunderbolt temperature measuring
> 
> 
> From my poking and prodding,  I think the temperature sensor 
> serves two purposes.  First as an environmental alarm.  
> Second as compensation for temperature effects on the system 
> as a whole.  As such,  you want it near where it was.  
> Sticking it on the oscillator would mask a lot of the ambient 
> temp changes that it is making adjustments for.
> 
> Another thing to consider is the difference in the thermal 
> mass / time constant of a DIP package and the SO-8 package.  
> The DIP will respond more slowly to temperature changes.  It 
> is not known how that might affect the oscillator 
> disciplining algorithm.
> 
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>