jfetload.c

ngspice又一个电子CAD仿真软件代码.功能更全

/**********
Copyright 1990 Regents of the University of California.  All rights reserved.
Author: 1985 Thomas L. Quarles
Modified: 2000 AlansFixes
Sydney University mods Copyright(c) 1989 Anthony E. Parker, David J. Skellern
	Laboratory for Communication Science Engineering
	Sydney University Department of Electrical Engineering, Australia
**********/

#include "ngspice.h"
#include "cktdefs.h"
#include "jfetdefs.h"
#include "const.h"
#include "trandefs.h"
#include "sperror.h"
#include "devdefs.h"
#include "suffix.h"

int
JFETload(GENmodel *inModel, CKTcircuit *ckt)
        /* actually load the current resistance value into the 
         * sparse matrix previously provided 
         */
{
    JFETmodel *model = (JFETmodel*)inModel;
    JFETinstance *here;
    double beta;
    double betap;
    double capgd;
    double capgs;
    double cd;
    double cdhat = 0.0;
    double cdrain;
    double cdreq;
    double ceq;
    double ceqgd;
    double ceqgs;
    double cg;
    double cgd;
    double cghat = 0.0;
    double csat;
    double czgd;
    double czgdf2;
    double czgs;
    double czgsf2;
    double delvds;
    double delvgd;
    double delvgs;
    double evgd;
    double evgs;
    double fcpb2;
    double gdpr;
    double gds;
    double geq;
    double ggd;
    double ggs;
    double gm;
    double gspr;
    double sarg;
    double twop;
    double vds;
    double vgd;
    double vgdt;
    double vgs;
    double vgst;
    double xfact;
    /* Modification for Sydney University JFET model */
    double vto;
    double apart,cpart;
    double Bfac;
    /* end Sydney University mod. */
    int icheck;
    int ichk1;
    int error;
    
    double arg, vt_temp;

    double m;

    /*  loop through all the models */
    for( ; model != NULL; model = model->JFETnextModel ) {

        /* loop through all the instances of the model */
        for (here = model->JFETinstances; here != NULL ;
                here=here->JFETnextInstance) {
	    if (here->JFETowner != ARCHme) continue;

            /*
             *  dc model parameters 
             */
            beta = model->JFETbeta * here->JFETarea;
            gdpr=model->JFETdrainConduct*here->JFETarea;
            gspr=model->JFETsourceConduct*here->JFETarea;
            csat=here->JFETtSatCur*here->JFETarea;
            /*
             *    initialization
             */
            icheck=1;
            if( ckt->CKTmode & MODEINITSMSIG) {
                vgs= *(ckt->CKTstate0 + here->JFETvgs);
                vgd= *(ckt->CKTstate0 + here->JFETvgd);
            } else if (ckt->CKTmode & MODEINITTRAN) {
                vgs= *(ckt->CKTstate1 + here->JFETvgs);
                vgd= *(ckt->CKTstate1 + here->JFETvgd);
            } else if ( (ckt->CKTmode & MODEINITJCT) &&
                    (ckt->CKTmode & MODETRANOP) &&
                    (ckt->CKTmode & MODEUIC) ) {
                vds=model->JFETtype*here->JFETicVDS;
                vgs=model->JFETtype*here->JFETicVGS;
                vgd=vgs-vds;
            } else if ( (ckt->CKTmode & MODEINITJCT) &&
                    (here->JFEToff == 0)  ) {
                vgs = -1;
                vgd = -1;
            } else if( (ckt->CKTmode & MODEINITJCT) ||
                    ((ckt->CKTmode & MODEINITFIX) && (here->JFEToff))) {
                vgs = 0;
                vgd = 0;
            } else {
#ifndef PREDICTOR
                if(ckt->CKTmode & MODEINITPRED) {
                    xfact=ckt->CKTdelta/ckt->CKTdeltaOld[1];
                    *(ckt->CKTstate0 + here->JFETvgs)= 
                            *(ckt->CKTstate1 + here->JFETvgs);
                    vgs=(1+xfact)* *(ckt->CKTstate1 + here->JFETvgs)-xfact*
                            *(ckt->CKTstate2 + here->JFETvgs);
                    *(ckt->CKTstate0 + here->JFETvgd)= 
                            *(ckt->CKTstate1 + here->JFETvgd);
                    vgd=(1+xfact)* *(ckt->CKTstate1 + here->JFETvgd)-xfact*
                            *(ckt->CKTstate2 + here->JFETvgd);
                    *(ckt->CKTstate0 + here->JFETcg)= 
                            *(ckt->CKTstate1 + here->JFETcg);
                    *(ckt->CKTstate0 + here->JFETcd)= 
                            *(ckt->CKTstate1 + here->JFETcd);
                    *(ckt->CKTstate0 + here->JFETcgd)=
                            *(ckt->CKTstate1 + here->JFETcgd);
                    *(ckt->CKTstate0 + here->JFETgm)=
                            *(ckt->CKTstate1 + here->JFETgm);
                    *(ckt->CKTstate0 + here->JFETgds)=
                            *(ckt->CKTstate1 + here->JFETgds);
                    *(ckt->CKTstate0 + here->JFETggs)=
                            *(ckt->CKTstate1 + here->JFETggs);
                    *(ckt->CKTstate0 + here->JFETggd)=
                            *(ckt->CKTstate1 + here->JFETggd);
                } else {
#endif /*PREDICTOR*/
                    /*
                     *  compute new nonlinear branch voltages 
                     */
                    vgs=model->JFETtype*
                        (*(ckt->CKTrhsOld+ here->JFETgateNode)-
                        *(ckt->CKTrhsOld+ 
                        here->JFETsourcePrimeNode));
                    vgd=model->JFETtype*
                        (*(ckt->CKTrhsOld+here->JFETgateNode)-
                        *(ckt->CKTrhsOld+
                        here->JFETdrainPrimeNode));
#ifndef PREDICTOR
                }
#endif /*PREDICTOR*/
                delvgs=vgs- *(ckt->CKTstate0 + here->JFETvgs);
                delvgd=vgd- *(ckt->CKTstate0 + here->JFETvgd);
                delvds=delvgs-delvgd;
                cghat= *(ckt->CKTstate0 + here->JFETcg)+ 
                        *(ckt->CKTstate0 + here->JFETggd)*delvgd+
                        *(ckt->CKTstate0 + here->JFETggs)*delvgs;
                cdhat= *(ckt->CKTstate0 + here->JFETcd)+
                        *(ckt->CKTstate0 + here->JFETgm)*delvgs+
                        *(ckt->CKTstate0 + here->JFETgds)*delvds-
                        *(ckt->CKTstate0 + here->JFETggd)*delvgd;
                /*
                 *   bypass if solution has not changed 
                 */
                if((ckt->CKTbypass) &&
                    (!(ckt->CKTmode & MODEINITPRED)) &&
                    (fabs(delvgs) < ckt->CKTreltol*MAX(fabs(vgs),
                        fabs(*(ckt->CKTstate0 + here->JFETvgs)))+
                        ckt->CKTvoltTol) )
        if ( (fabs(delvgd) < ckt->CKTreltol*MAX(fabs(vgd),
                        fabs(*(ckt->CKTstate0 + here->JFETvgd)))+
                        ckt->CKTvoltTol))
        if ( (fabs(cghat-*(ckt->CKTstate0 + here->JFETcg)) 
                        < ckt->CKTreltol*MAX(fabs(cghat),
                        fabs(*(ckt->CKTstate0 + here->JFETcg)))+
                        ckt->CKTabstol) ) if ( /* hack - expression too big */
                    (fabs(cdhat-*(ckt->CKTstate0 + here->JFETcd))
                        < ckt->CKTreltol*MAX(fabs(cdhat),
                        fabs(*(ckt->CKTstate0 + here->JFETcd)))+
                        ckt->CKTabstol) ) {

                    /* we can do a bypass */
                    vgs= *(ckt->CKTstate0 + here->JFETvgs);
                    vgd= *(ckt->CKTstate0 + here->JFETvgd);
                    vds= vgs-vgd;
                    cg= *(ckt->CKTstate0 + here->JFETcg);
                    cd= *(ckt->CKTstate0 + here->JFETcd);
                    cgd= *(ckt->CKTstate0 + here->JFETcgd);
                    gm= *(ckt->CKTstate0 + here->JFETgm);
                    gds= *(ckt->CKTstate0 + here->JFETgds);
                    ggs= *(ckt->CKTstate0 + here->JFETggs);
                    ggd= *(ckt->CKTstate0 + here->JFETggd);
                    goto load;
                }
                /*
                 *  limit nonlinear branch voltages 
                 */
                ichk1=1;
                vgs = DEVpnjlim(vgs,*(ckt->CKTstate0 + here->JFETvgs),
                        (here->JFETtemp*CONSTKoverQ), here->JFETvcrit, &icheck);
                vgd = DEVpnjlim(vgd,*(ckt->CKTstate0 + here->JFETvgd),
                        (here->JFETtemp*CONSTKoverQ), here->JFETvcrit,&ichk1);
                if (ichk1 == 1) {
                    icheck=1;
                }
                vgs = DEVfetlim(vgs,*(ckt->CKTstate0 + here->JFETvgs),
                        model->JFETthreshold);
                vgd = DEVfetlim(vgd,*(ckt->CKTstate0 + here->JFETvgd),
                        model->JFETthreshold);
            }
            /*
             *   determine dc current and derivatives 
             */
            vds=vgs-vgd;
            
            vt_temp=here->JFETtemp*CONSTKoverQ;
            if (vgs < -3*vt_temp) {
                arg=3*vt_temp/(vgs*CONSTe);
                arg = arg * arg * arg;
                cg = -csat*(1+arg)+ckt->CKTgmin*vgs;
                ggs = csat*3*arg/vgs+ckt->CKTgmin;
            } else {
                evgs = exp(vgs/vt_temp);
                ggs = csat*evgs/vt_temp+ckt->CKTgmin;
                cg = csat*(evgs-1)+ckt->CKTgmin*vgs;
            }
            
            if (vgd < -3*vt_temp) {
                arg=3*vt_temp/(vgd*CONSTe);
                arg = arg * arg * arg;
                cgd = -csat*(1+arg)+ckt->CKTgmin*vgd;
                ggd = csat*3*arg/vgd+ckt->CKTgmin;
            } else {
                evgd = exp(vgd/vt_temp);
                ggd = csat*evgd/vt_temp+ckt->CKTgmin;
                cgd = csat*(evgd-1)+ckt->CKTgmin*vgd;
            }
            
            cg = cg+cgd;

	    /* Modification for Sydney University JFET model */
            vto = model->JFETthreshold;
            if (vds >= 0) {
                vgst = vgs - vto;
                /*
                 * compute drain current and derivatives for normal mode
                 */
                if (vgst <= 0) {
                    /*
                     * normal mode, cutoff region
                     */
                    cdrain = 0;
                    gm = 0;
                    gds = 0;
                } else {
                    betap = beta*(1 + model->JFETlModulation*vds);
                    Bfac = model->JFETbFac;