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Introducing mobility reduction over Vgs. Model parameter: theta

This commit is contained in:
dwarning 2018-11-25 00:53:39 +01:00 committed by Holger Vogt
parent 96a5ea0353
commit 8b424dd3d3
6 changed files with 37 additions and 17 deletions
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1
src/spicelib/devices/vdmos/vdmos.c
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@ -64,6 +64,7 @@ IFparm VDMOSmPTable[] = { /* model parameters */
IOP("kp", VDMOS_MOD_KP, IF_REAL, "Transconductance parameter"),
IOP("phi", VDMOS_MOD_PHI, IF_REAL, "Surface potential"),
IOP("lambda",VDMOS_MOD_LAMBDA,IF_REAL, "Channel length modulation"),
IOP("theta", VDMOS_MOD_THETA, IF_REAL, "Vgs dependence on mobility"),
IOP("rd", VDMOS_MOD_RD, IF_REAL, "Drain ohmic resistance"),
IOP("rs", VDMOS_MOD_RS, IF_REAL, "Source ohmic resistance"),
IOP("rg", VDMOS_MOD_RG, IF_REAL, "Gate ohmic resistance"),

4
src/spicelib/devices/vdmos/vdmosdefs.h
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@ -265,8 +265,10 @@ typedef struct sVDMOSmodel { /* model structure for a resistor */
double VDMOSvt0; /* input - use tVto */
double VDMOSphi; /* input - use tPhi */
double VDMOSlambda;
double VDMOStheta;
double VDMOSfNcoef;
double VDMOSfNexp;
double VDMOScgdmin;
double VDMOScgdmax;
double VDMOSa;
@ -313,6 +315,7 @@ typedef struct sVDMOSmodel { /* model structure for a resistor */
unsigned VDIOdepletionCapCoeffGiven :1;
unsigned VDMOSphiGiven :1;
unsigned VDMOSlambdaGiven :1;
unsigned VDMOSthetaGiven :1;
unsigned VDMOStnomGiven :1;
unsigned VDMOSfNcoefGiven :1;
unsigned VDMOSfNexpGiven :1;
@ -367,6 +370,7 @@ enum {
VDMOS_MOD_KP,
VDMOS_MOD_PHI,
VDMOS_MOD_LAMBDA,
VDMOS_MOD_THETA,
VDMOS_MOD_RD,
VDMOS_MOD_RS,
VDMOS_MOD_RG,

39
src/spicelib/devices/vdmos/vdmosload.c
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@ -282,53 +282,58 @@ VDMOSload(GENmodel *inModel, CKTcircuit *ckt)
*/
double betap;
double vgst;
double onfg, fgate, Betam, dfgdvg;
von = (model->VDMOSvt0*model->VDMOStype);
vgst = (here->VDMOSmode == 1 ? vgs : vgd) - von;
vdsat = MAX(vgst, 0);
onfg = 1.0+model->VDMOStheta*vgst;
fgate = 1.0/onfg;
Betam = Beta * fgate;
dfgdvg = -model->VDMOStheta*fgate*fgate;
/* drain current including subthreshold current
* numerical differentiation for gd and gm with a delta of 2 mV */
if (model->VDMOSksubthresGiven && (here->VDMOSmode == 1)) {
double delta = 0.001;
cdrain = cweakinv(model->VDMOSksubthres, model->VDMOSsubshift, vgst, vds, model->VDMOSlambda,
Beta, vt, model->VDMOSmtr);
Betam, vt, model->VDMOSmtr);
/* gd */
double vds1 = vds + delta;
double cdrp = cweakinv(model->VDMOSksubthres, model->VDMOSsubshift, vgst, vds1, model->VDMOSlambda,
Beta, vt, model->VDMOSmtr);
Betam, vt, model->VDMOSmtr);
vds1 = vds - delta;
double cdrm = cweakinv(model->VDMOSksubthres, model->VDMOSsubshift, vgst, vds1, model->VDMOSlambda,
Beta, vt, model->VDMOSmtr);
Betam, vt, model->VDMOSmtr);
here->VDMOSgds = (cdrp - cdrm) / (2. * delta);
/* gm */
double vgst1 = vgst + delta;
cdrp = cweakinv(model->VDMOSksubthres, model->VDMOSsubshift, vgst1, vds, model->VDMOSlambda,
Beta, vt, model->VDMOSmtr);
Betam, vt, model->VDMOSmtr);
vgst1 = vgst - delta;
cdrm = cweakinv(model->VDMOSksubthres, model->VDMOSsubshift, vgst1, vds, model->VDMOSlambda,
Beta, vt, model->VDMOSmtr);
here->VDMOSgm = (cdrp - cdrm) / (2. * delta);
Betam, vt, model->VDMOSmtr);
here->VDMOSgm = (cdrp - cdrm) / (2. * delta) * fgate + dfgdvg * cdrain;
}
else if (model->VDMOSsubslGiven && (here->VDMOSmode == 1)) {
double delta = 0.001;
cdrain = cweakinv2(model->VDMOSsubsl, model->VDMOSsubshift, vgst, vds, model->VDMOSlambda,
Beta, vt, model->VDMOSmtr);
Betam, vt, model->VDMOSmtr);
/* gd */
double vds1 = vds + delta;
double cdrp = cweakinv2(model->VDMOSsubsl, model->VDMOSsubshift, vgst, vds1, model->VDMOSlambda,
Beta, vt, model->VDMOSmtr);
Betam, vt, model->VDMOSmtr);
vds1 = vds - delta;
double cdrm = cweakinv2(model->VDMOSsubsl, model->VDMOSsubshift, vgst, vds1, model->VDMOSlambda,
Beta, vt, model->VDMOSmtr);
Betam, vt, model->VDMOSmtr);
here->VDMOSgds = (cdrp - cdrm) / (2. * delta);
/* gm */
double vgst1 = vgst + delta;
cdrp = cweakinv2(model->VDMOSsubsl, model->VDMOSsubshift, vgst1, vds, model->VDMOSlambda,
Beta, vt, model->VDMOSmtr);
Betam, vt, model->VDMOSmtr);
vgst1 = vgst - delta;
cdrm = cweakinv2(model->VDMOSsubsl, model->VDMOSsubshift, vgst1, vds, model->VDMOSlambda,
Beta, vt, model->VDMOSmtr);
here->VDMOSgm = (cdrp - cdrm) / (2. * delta);
Betam, vt, model->VDMOSmtr);
here->VDMOSgm = (cdrp - cdrm) / (2. * delta) * fgate + dfgdvg * cdrain;
} else {
if (vgst <= 0) {
/*
@ -343,20 +348,20 @@ VDMOSload(GENmodel *inModel, CKTcircuit *ckt)
*/
/* scale vds with mtr */
double mtr = model->VDMOSmtr;
betap = Beta*(1 + model->VDMOSlambda*(vds*here->VDMOSmode));
betap = Betam*(1 + model->VDMOSlambda*(vds*here->VDMOSmode));
if (vgst <= (vds * here->VDMOSmode) * mtr) {
cdrain = betap*vgst*vgst*.5;
here->VDMOSgm = betap*vgst;
here->VDMOSgds = model->VDMOSlambda*Beta*vgst*vgst*.5;
here->VDMOSgm = betap*vgst * fgate + dfgdvg * cdrain;
here->VDMOSgds = model->VDMOSlambda*Betam*vgst*vgst*.5;
} else {
/*
* linear region
*/
cdrain = betap * (vds * here->VDMOSmode) * mtr *
(vgst - .5 * (vds*here->VDMOSmode) * mtr);
here->VDMOSgm = betap * (vds * here->VDMOSmode) * mtr;
here->VDMOSgm = betap * (vds * here->VDMOSmode) * mtr * fgate + dfgdvg * cdrain;
here->VDMOSgds = betap * (vgst - (vds * here->VDMOSmode) * mtr) +
model->VDMOSlambda * Beta *
model->VDMOSlambda * Betam *
(vds * here->VDMOSmode) * mtr *
(vgst - .5 * (vds * here->VDMOSmode) * mtr);
}

3
src/spicelib/devices/vdmos/vdmosmask.c
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@ -36,6 +36,9 @@ VDMOSmAsk(CKTcircuit *ckt, GENmodel *inst, int which, IFvalue *value)
case VDMOS_MOD_LAMBDA:
value->rValue = model->VDMOSlambda;
return(OK);
case VDMOS_MOD_THETA:
value->rValue = model->VDMOStheta;
return(OK);
case VDMOS_MOD_RD:
value->rValue = model->VDMOSdrainResistance;
return(OK);

4
src/spicelib/devices/vdmos/vdmosmpar.c
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@ -35,6 +35,10 @@ VDMOSmParam(int param, IFvalue *value, GENmodel *inModel)
model->VDMOSlambda = value->rValue;
model->VDMOSlambdaGiven = TRUE;
break;
case VDMOS_MOD_THETA:
model->VDMOStheta = value->rValue;
model->VDMOSthetaGiven = TRUE;
break;
case VDMOS_MOD_RD:
model->VDMOSdrainResistance = value->rValue;
model->VDMOSdrainResistanceGiven = TRUE;

3
src/spicelib/devices/vdmos/vdmosset.c
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@ -54,6 +54,9 @@ VDMOSsetup(SMPmatrix *matrix, GENmodel *inModel, CKTcircuit *ckt,
if (!model->VDMOSlambdaGiven) {
model->VDMOSlambda = 0;
}
if (!model->VDMOSthetaGiven) {
model->VDMOStheta = 0;
}
if (!model->VDMOSfNcoefGiven) {
model->VDMOSfNcoef = 0;
}