Designer’s Guide Community

‹ Previous topic | Next topic ›

Pages: 1

vbic HBT rth & cth conversion SpectreRF to HSPICE (Read 3269 times)

imtired

Junior Member

Offline

Posts: 23
Santa Rosa

vbic HBT rth & cth conversion SpectreRF to HSPICE
Nov 12^th, 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

IP Logged

Geoffrey_Coram

Senior Fellow

Offline

Posts: 1999
Massachusetts, USA

Re: vbic HBT rth & cth conversion SpectreRF to HSP
Reply #1 - Nov 12^th, 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).

If at first you do succeed, STOP, raise your standards, and stop wasting your time.

IP Logged

imtired Junior Member Offline Posts: 23 Santa Rosa	Re: vbic HBT rth & cth conversion SpectreRF to HSP Reply #2 - Nov 12^th, 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.
Back to top	IP Logged

Pages: 1

‹ Previous topic | Next topic ›