HILBORN@scarolina.CSNET.UUCP (02/11/87)
In attempting to use SPICE to analyse bipolar circuits, I find that I am
unfamiliar with some of the bipolar transistor model parameters listed in
the SPICE 2G.1 Users Guide. I was wondering if anyone might be able to
refer me to the appropriate documents in which I might find an illuminating
discussion in regard to the following parameters:
(1) "RBM" and "IRB", used in the equations for the base resistance.
(2) "XTF", "ITF", "VTF", and "PTF", used in the equations for the
effective transit time, "TFF".
I will certainly appreciate any information provided in this matter.
Thank you.
Sam Hilborn (HILBORN@SCAROLINA.EDU) clark@seraphim.harvard.edu (James J. Clark) (09/06/87)
Spice model parameters are provided by MOSIS whenever they send back a batch of fabricated integrated circuits to the designers. (note: MOSIS is DARPA sponsored service which interfaces between designers of integrated circuits and various fabrication facilities) They do tests on the wafers that the chips were located on to get the parameter values. One should be warned, however, that sometimes these measurements are not too accurate and may even be way off (this happened to me once). So one should look at the parameter values closely - if they look reasonable then they should be alright to use. If you want these typical spice parameters you may want to e-mail a request to MOSIS (at mosis@isi.b.edu) or you can e-mail myself and I will send you a few sets. James J. Clark Division of Applied Sciences Harvard University clark@seraphim.harvard.edu s beaarnMessaMessaMce irives w
daasch@psueea.UUCP (Robert Daasch) (09/09/87)
In article <2804@husc6.UUCP> clark@seraphim.harvard.edu (James J. Clark) writes: >Spice model parameters are provided by MOSIS whenever they ... > One should be warned, however, that sometimes these >measurements are not too accurate and may even be way off >(this happened to me once). So one should look at the >parameter values closely - if they look reasonable then they >should be alright to use. > The most glaring of errors I have seen from MOSIS was a run with CMOSP VTO > 0 and XJ = 40 centimeters! A word to the wise... Rob D. ..!tektronix!psueea!daasch daasch@ee.pdx.edu.CSNET