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https://designers-guide.org/forum/YaBB.pl Modeling >> Semiconductor Devices >> The high temperature spice model https://designers-guide.org/forum/YaBB.pl?num=1205980628 Message started by dandelion on Mar 19th, 2008, 7:36pm |
Title: The high temperature spice model Post by dandelion on Mar 19th, 2008, 7:36pm Hi, I am designing a circuit which contains a overheat block. The detection thershold is 160'C and if the 160'C is reached, the block will be shutdown. But I checked the spice model and found the model is only for -40'C-125'C. These is no model descriptions above 125'C. Communicated with the Foundry, they said the above 125 model is not measured. But for the overheat sub-block, i must simulated it wit 160'C. I wonder is there any risks in it? The actural silicon will be much descranpancy from the design? Pls. share with your experienc. Thanks |
Title: Re: The high temperature spice model Post by Geoffrey_Coram on Mar 20th, 2008, 6:22am I'd suggest you do some plots of all the currents and capacitances as you step the temperature from 100 to 200 in 10-degree steps. Make sure they look reasonable. Some models have linear temperature effects, and you might find that eg VSAT becomes negative at 190 degrees, which would be a strong indication that you won't get the right answer at 160. BSIM4 has VSAT_T = VSAT - AT * (T/Tref - 1); |
Title: Re: The high temperature spice model Post by thechopper on Mar 20th, 2008, 7:10am Certainly leakage currents will be a headache if not properly modeled. Usually, somewhere between 110 to 130C is where the leakage currents tend to play a role in the total error you get for several analog circuits. I usually simulate up to 165C and at such temperature a common concern is balancing leakage currents in precision analog circuits. You might want to consider this too. Tosei |
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