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Update disto model to spice3 and added a note about high level injection.

This commit is contained in:
pnenzi 2003-10-15 21:31:48 +00:00
parent 38252ebdbe
commit 49d77b9f3c
1 changed files with 46 additions and 24 deletions
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70
src/spicelib/devices/dio/diodset.c
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@ -14,6 +14,14 @@ Modified by Dietmar Warning 2003
/* actually load the current resistance value into the sparse matrix /* actually load the current resistance value into the sparse matrix
* previously provided - for distortion analysis */ * previously provided - for distortion analysis */
/*
* For some unknown reason the code in this fuction was based on the
* spice2 diode implementation (the one with -5 nVt). I have changed
* it with spice3 implementation.
*
* Paolo Nenzi 2003
*/
int int
DIOdSetup(DIOmodel *model, CKTcircuit *ckt) DIOdSetup(DIOmodel *model, CKTcircuit *ckt)
{ {
@ -48,9 +56,14 @@ DIOdSetup(DIOmodel *model, CKTcircuit *ckt)
here=here->DIOnextInstance) { here=here->DIOnextInstance) {
if (here->DIOowner != ARCHme) continue; if (here->DIOowner != ARCHme) continue;
/* /*
* this routine loads diodes for dc and transient analyses. * this routine loads diodes for dc and transient analyses.
*/ * PN 2003: High level injection is not taken into
* account, since resulting equations are
* very complex to deal with.
*
* This is an old analysis anyway....
*/
csat=(here->DIOtSatCur*here->DIOarea+here->DIOtSatSWCur*here->DIOpj)*here->DIOm; csat=(here->DIOtSatCur*here->DIOarea+here->DIOtSatSWCur*here->DIOpj)*here->DIOm;
vt = CONSTKoverQ * here->DIOtemp; vt = CONSTKoverQ * here->DIOtemp;
@ -59,36 +72,45 @@ DIOdSetup(DIOmodel *model, CKTcircuit *ckt)
*(ckt->CKTrhsOld + (here->DIOnegNode)); *(ckt->CKTrhsOld + (here->DIOnegNode));
/* /*
* compute derivatives * compute derivatives
*/ * Note: pn 2003 changed the code to the new spice 3 code
if (vd >= -5*vte) { */
if (vd >= -3*vte) { /* forward */
evd = exp(vd/vte); evd = exp(vd/vte);
cd = csat*(evd-1)+ckt->CKTgmin*vd; cd = csat*(evd-1);
gd = csat*evd/vte+ckt->CKTgmin; gd = csat*evd/vte;
if((model->DIOforwardKneeCurrentGiven) && (model->DIOforwardKneeCurrent > 0.0) && (cd > 1.0e-18) ) {
ikf_area_m = model->DIOforwardKneeCurrent*here->DIOarea*here->DIOm; g2 = 0.5 * gd / vte;
sqrt_ikf = sqrt(cd/ikf_area_m);
gd = ((1+sqrt_ikf)*gd - cd*gd/(2*sqrt_ikf*ikf_area_m))/(1+2*sqrt_ikf+cd/ikf_area_m)+ckt->CKTgmin;
}
g2 = 0.5*(gd-ckt->CKTgmin)/vte;
cdiff2 = g2 * here->DIOtTransitTime; cdiff2 = g2 * here->DIOtTransitTime;
g3 = g2/3/vte; g3 = g2 / 3 / vte;
cdiff3 = g3 * here->DIOtTransitTime; cdiff3 = g3 * here->DIOtTransitTime;
gd = gd + ckt->CKTgmin;
} }
else if((!(here->DIOtBrkdwnV))|| else if((!(here->DIOtBrkdwnV))||
(vd >= -here->DIOtBrkdwnV)) { (vd >= -here->DIOtBrkdwnV)) { /* reverse */
gd = -csat/vd+ckt->CKTgmin;
g2=g3=cdiff2=cdiff3=0.0; arg=3*vte/(vd*CONSTe);
/* off */ arg = arg * arg * arg;
cd = -csat * (1 + arg);
gd = csat * 3 * arg / vd;
g2 = -4 * gd / vd;
g3 = 5 * g2 / vd;
cdiff2 = cdiff3 = 0.0;
gd = gd + ckt->CKTgmin;
} }
else { else { /* breakdown*/
/* reverse breakdown */
/* why using csat instead of breakdowncurrent? */ /* why using csat instead of breakdowncurrent? */
evrev=exp(-(here->DIOtBrkdwnV+vd)/vt); evrev=exp(-(here->DIOtBrkdwnV+vd)/vt);
cd = -csat*evrev;
gd = csat*evrev/vte;
/* /*
cd = -csat*(evrev-1+here->DIOtBrkdwnV/vt); * cd = -csat*(evrev-1+here->DIOtBrkdwnV/vt);
*/ */
/* should there be a minus here above? */ /* should there be a minus here above?
*/
gd=csat*evrev/vt; gd=csat*evrev/vt;
g2 = -gd/2/vt; g2 = -gd/2/vt;
g3 = -g2/3/vt; g3 = -g2/3/vt;