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Design >> Analog Design >> Accuracy device foundry models with temperature
https://designers-guide.org/forum/YaBB.pl?num=1251741693

Message started by Visjnoe on Aug 31^st, 2009, 11:01am

Title: Accuracy device foundry models with temperature
Post by Visjnoe on Aug 31^st, 2009, 11:01am

Dear all,

At the moment, I'm measuring a circuit which shows faulty behavior at about 70deg. This circuit has been simulated uptil 125deg.

However, I can reproduce the faulty behavior by putting the temperature (in simulation) to 240deg. This makes me think there's a modeling error in some of the foundry device models...

Does anybody have experience with foundry modeling errors that result in such a large deviation between simulation/measurement, especially over temperature?

Regards

Title: Re: Accuracy device foundry models with temperature
Post by solidstate on Aug 31^st, 2009, 12:34pm

What kind of faulty behavior do you observe? What kind of circuit is this? Which process? Which foundry? It's likely that the error mechanism has a different tipping point for different process corners, or that the presence of device mismatch anticipates the onset..

Title: Re: Accuracy device foundry models with temperature
Post by Visjnoe on Sep 1^st, 2009, 12:13am

Maybe the intention of my question was a bit unclear. I do not want to discuss my specific case in depth, I just wanted to know if other people have encountered similar (or minor) discrepancies between simulation and measurement over temperature (for any given circuit).

Regards

Title: Re: Accuracy device foundry models with temperature
Post by ywguo on Sep 8^th, 2009, 12:47am

Hi Visjone,

Most foundries provide SPICE models which fit the measurement data from -40 degC to 125 degC. I have never designed any circuitry that runs as high as 240 degC. Are you sure the SPICE model covers so high temperature?

Best Regards,
Yawei