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https://designers-guide.org/forum/YaBB.pl Modeling >> Semiconductor Devices >> vbic HBT rth & cth conversion SpectreRF to HSPICE https://designers-guide.org/forum/YaBB.pl?num=1194897900 Message started by imtired on Nov 12th, 2007, 12:05pm |
Title: vbic HBT rth & cth conversion SpectreRF to HSPICE Post by imtired on Nov 12th, 2007, 12:05pm HI all, I am in need of some help converting VBIC HBT parameter units for the self-heating thermal resistance and capacitance "rth" and "cth" from SpectreRF to HSPICE. I found that the untis in SPectreRF for these two parameters are ohms and Farads, respectively, but in HSPICE the units are in K/W and J/K. Does anyone know how to do this? Thanks, RU |
Title: Re: vbic HBT rth & cth conversion SpectreRF to HSP Post by Geoffrey_Coram on Nov 12th, 2007, 1:04pm I think the HSpice units are correct, and the Spectre folks are perhaps a little sloppy. You shouldn't need any conversion. "rth" is implemented as a resistor (in terms of its matrix stamp), but the "current" that flows through it is heat (power) and the "voltage" across it is really temperature (in Kelvin). |
Title: Re: vbic HBT rth & cth conversion SpectreRF to HSP Post by imtired on Nov 12th, 2007, 6:24pm So it was just a matter of describing the units in different domains, HSpice in thermal domain, and SpectreRF in the electrical domain. That makes more sense to me now, and so I don't need to do any conversion of the parameters Rth and Cth. Thanks Geoffrey. |
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