I have this circuit:
http://i812.photobucket.com/albums/zz41/uofmx12/E21ckt-2.jpg
I measured, using multisim, Va=10.1V and Vb=.68V and I =9.4mA.
If using i=Is(e^(v/(nVt))-1) where n=1.5 and Vt=.0259V. Is v my Vb? Using that and solving for Is, I get .235nA.
http://i812.photobucket.com/albums/zz41/uofmx12/E21ckt-2.jpg
I measured, using multisim, Va=10.1V and Vb=.68V and I =9.4mA.
If using i=Is(e^(v/(nVt))-1) where n=1.5 and Vt=.0259V. Is v my Vb? Using that and solving for Is, I get .235nA.