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separate diode bottom and sidewall contributions for depletion capacitance

This commit is contained in:
dwarning 2015-03-06 20:39:17 +01:00 committed by rlar
parent ea4c438311
commit 032b1c32c4
3 changed files with 64 additions and 34 deletions
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2
src/spicelib/devices/dio/diodefs.h
View File

@ -82,6 +82,8 @@ typedef struct sDIOinstance {
double DIOtDepCap; /* temperature adjusted transition point in */
/* the curve matching (Fc * Vj ) */
double DIOtDepSWCap; /* temperature adjusted transition point in */
/* the curve matching (Fcs * Vjs ) */
double DIOtSatCur; /* temperature adjusted saturation current */
double DIOtSatSWCur; /* temperature adjusted side wall saturation current */
double DIOtTunSatCur; /* tunneling saturation current */

86
src/spicelib/devices/dio/dioload.c
View File

@ -25,7 +25,7 @@ DIOload(GENmodel *inModel, CKTcircuit *ckt)
double arg;
double argsw;
double capd;
double cd;
double cd, cdb, cdsw;
double cdeq;
double cdhat;
double ceq;
@ -45,7 +45,7 @@ DIOload(GENmodel *inModel, CKTcircuit *ckt)
double delvd; /* change in diode voltage temporary */
double evd;
double evrev;
double gd;
double gd, gdb, gdsw;
double geq;
double gspr; /* area-scaled conductance */
double sarg;
@ -60,6 +60,7 @@ DIOload(GENmodel *inModel, CKTcircuit *ckt)
int Check;
int error;
int SenCond=0; /* sensitivity condition */
double diffcharge, diffchargeSW, deplcharge, deplchargeSW, diffcap, diffcapSW, deplcap, deplcapSW;
/* loop through all the diode models */
for( ; model != NULL; model = model->DIOnextModel ) {
@ -84,7 +85,11 @@ DIOload(GENmodel *inModel, CKTcircuit *ckt)
}
cd = 0.0;
cdb = 0.0;
cdsw = 0.0;
gd = 0.0;
gdb = 0.0;
gdsw = 0.0;
csat = here->DIOtSatCur;
csatsw = here->DIOtSatSWCur;
gspr = here->DIOtConductance * here->DIOarea;
@ -197,22 +202,22 @@ next1: if (model->DIOsatSWCurGiven) { /* sidewall current */
if (vd >= -3*vtesw) { /* forward */
evd = exp(vd/vtesw);
cd = csatsw*(evd-1);
gd = csatsw*evd/vtesw;
cdsw = csatsw*(evd-1);
gdsw = csatsw*evd/vtesw;
} else if((!(model->DIObreakdownVoltageGiven)) ||
vd >= -here->DIOtBrkdwnV) { /* reverse */
argsw = 3*vtesw/(vd*CONSTe);
argsw = argsw * argsw * argsw;
cd = -csatsw*(1+argsw);
gd = csatsw*3*argsw/vd;
cdsw = -csatsw*(1+argsw);
gdsw = csatsw*3*argsw/vd;
} else { /* breakdown */
evrev = exp(-(here->DIOtBrkdwnV+vd)/vtebrk);
cd = -csatsw*evrev;
gd = csatsw*evrev/vtebrk;
cdsw = -csatsw*evrev;
gdsw = csatsw*evrev/vtebrk;
}
@ -227,22 +232,22 @@ next1: if (model->DIOsatSWCurGiven) { /* sidewall current */
if (vd >= -3*vte) { /* bottom current forward */
evd = exp(vd/vte);
cd = cd + csat*(evd-1);
gd = gd + csat*evd/vte;
cdb = csat*(evd-1);
gdb = csat*evd/vte;
} else if((!(model->DIObreakdownVoltageGiven)) ||
vd >= -here->DIOtBrkdwnV) { /* reverse */
arg = 3*vte/(vd*CONSTe);
arg = arg * arg * arg;
cd = cd - csat*(1+arg);
gd = gd + csat*3*arg/vd;
cdb = -csat*(1+arg);
gdb = csat*3*arg/vd;
} else { /* breakdown */
evrev = exp(-(here->DIOtBrkdwnV+vd)/vtebrk);
cd = cd - csat*evrev;
gd = gd + csat*evrev/vtebrk;
cdb = -csat*evrev;
gdb = csat*evrev/vtebrk;
}
@ -251,8 +256,8 @@ next1: if (model->DIOsatSWCurGiven) { /* sidewall current */
vtetun = model->DIOtunEmissionCoeff * vt;
evd = exp(-vd/vtetun);
cd = cd - here->DIOtTunSatSWCur * (evd - 1);
gd = gd + here->DIOtTunSatSWCur * evd / vtetun;
cdsw = cdsw - here->DIOtTunSatSWCur * (evd - 1);
gdsw = gdsw + here->DIOtTunSatSWCur * evd / vtetun;
}
@ -261,11 +266,13 @@ next1: if (model->DIOsatSWCurGiven) { /* sidewall current */
vtetun = model->DIOtunEmissionCoeff * vt;
evd = exp(-vd/vtetun);
cd = cd - here->DIOtTunSatCur * (evd - 1);
gd = gd + here->DIOtTunSatCur * evd / vtetun;
cdb = cdb - here->DIOtTunSatCur * (evd - 1);
gdb = gdb + here->DIOtTunSatCur * evd / vtetun;
}
cd = cdb + cdsw;
gd = gdb + gdsw;
if (vd >= -3*vte) { /* limit forward */
@ -299,28 +306,39 @@ next1: if (model->DIOsatSWCurGiven) { /* sidewall current */
* charge storage elements
*/
czero=here->DIOtJctCap;
czeroSW=here->DIOtJctSWCap;
if (vd < here->DIOtDepCap){
arg=1-vd/here->DIOtJctPot;
argSW=1-vd/here->DIOtJctSWPot;
sarg=exp(-here->DIOtGradingCoeff*log(arg));
sargSW=exp(-model->DIOgradingSWCoeff*log(argSW));
*(ckt->CKTstate0 + here->DIOcapCharge) =
here->DIOtTransitTime*cd+
here->DIOtJctPot*czero*(1-arg*sarg)/(1-here->DIOtGradingCoeff)+
here->DIOtJctSWPot*czeroSW*(1-argSW*sargSW)/(1-model->DIOgradingSWCoeff);
capd=here->DIOtTransitTime*gd+czero*sarg+czeroSW*sargSW;
deplcharge = here->DIOtJctPot*czero*(1-arg*sarg)/(1-here->DIOtGradingCoeff);
deplcap = czero*sarg;
} else {
czof2=czero/here->DIOtF2;
czof2SW=czeroSW/here->DIOtF2SW;
*(ckt->CKTstate0 + here->DIOcapCharge) =
here->DIOtTransitTime*cd+czero*here->DIOtF1+
czof2*(here->DIOtF3*(vd-here->DIOtDepCap)+(here->DIOtGradingCoeff/(here->DIOtJctPot+here->DIOtJctPot))*(vd*vd-here->DIOtDepCap*here->DIOtDepCap))+
czof2SW*(here->DIOtF3SW*(vd-here->DIOtDepCap)+(model->DIOgradingSWCoeff/(here->DIOtJctSWPot+here->DIOtJctSWPot))*(vd*vd-here->DIOtDepCap*here->DIOtDepCap));
capd=here->DIOtTransitTime*gd+
czof2*(here->DIOtF3+here->DIOtGradingCoeff*vd/here->DIOtJctPot)+
czof2SW*(here->DIOtF3SW+model->DIOgradingSWCoeff*vd/here->DIOtJctSWPot);
deplcharge = czero*here->DIOtF1+czof2*(here->DIOtF3*(vd-here->DIOtDepCap)+
(here->DIOtGradingCoeff/(here->DIOtJctPot+here->DIOtJctPot))*(vd*vd-here->DIOtDepCap*here->DIOtDepCap));
deplcap = czof2*(here->DIOtF3+here->DIOtGradingCoeff*vd/here->DIOtJctPot);
}
czeroSW=here->DIOtJctSWCap;
if (vd < here->DIOtDepSWCap){
argSW=1-vd/here->DIOtJctSWPot;
sargSW=exp(-model->DIOgradingSWCoeff*log(argSW));
deplchargeSW = here->DIOtJctSWPot*czeroSW*(1-argSW*sargSW)/(1-model->DIOgradingSWCoeff);
deplcapSW = czeroSW*sargSW;
} else {
czof2SW=czeroSW/here->DIOtF2SW;
deplchargeSW = czeroSW*here->DIOtF1+czof2SW*(here->DIOtF3SW*(vd-here->DIOtDepSWCap)+
(model->DIOgradingSWCoeff/(here->DIOtJctSWPot+here->DIOtJctSWPot))*(vd*vd-here->DIOtDepSWCap*here->DIOtDepSWCap));
deplcapSW = czof2SW*(here->DIOtF3SW+model->DIOgradingSWCoeff*vd/here->DIOtJctSWPot);
}
diffcharge = here->DIOtTransitTime*cdb;
diffchargeSW = here->DIOtTransitTime*cdsw;
*(ckt->CKTstate0 + here->DIOcapCharge) =
diffcharge + diffchargeSW + deplcharge + deplchargeSW;
diffcap = here->DIOtTransitTime*gdb;
diffcapSW = here->DIOtTransitTime*gdsw;
capd = diffcap + diffcapSW + deplcap + deplcapSW;
here->DIOcap = capd;
/*

10
src/spicelib/devices/dio/diotemp.c
View File

@ -179,6 +179,8 @@ DIOtemp(GENmodel *inModel, CKTcircuit *ckt)
/* same for Depletion Capacitance */
here->DIOtDepCap=model->DIOdepletionCapCoeff*
here->DIOtJctPot;
here->DIOtDepSWCap=model->DIOdepletionSWcapCoeff*
here->DIOtJctSWPot;
/* and Vcrit */
vte=model->DIOemissionCoeff*vt;
@ -192,6 +194,14 @@ DIOtemp(GENmodel *inModel, CKTcircuit *ckt)
"%s: junction potential VJ too large, limited to %f",
model->DIOmodName, here->DIOtJctPot);
}
/* limit sidewall junction potential to max of 1/FCS */
if(here->DIOtDepSWCap > 1.0) {
here->DIOtJctSWPot=1.0/model->DIOdepletionSWcapCoeff;
here->DIOtDepSWCap=model->DIOdepletionSWcapCoeff*here->DIOtJctSWPot;
SPfrontEnd->IFerrorf (ERR_WARNING,
"%s: junction potential VJS too large, limited to %f",
model->DIOmodName, here->DIOtJctSWPot);
}
/* and now to compute the breakdown voltage, again, using
* temperature adjusted basic parameters */