Remove instance parameter temp. To specify offset to ambient temperature use dtemp instead.

Remove temp update double application for beta and series resistances and fix derivatives for selfheating model.

src/spicelib/devices/vdmos/vdmos.c

@@ -16,7 +16,6 @@ IFparm VDMOSpTable[] = { /* parameters */
  IP("off",          VDMOS_OFF,        IF_FLAG,    "Device initially off"),
  IOPU("icvds",      VDMOS_IC_VDS,     IF_REAL,    "Initial D-S voltage"),
  IOPU("icvgs",      VDMOS_IC_VGS,     IF_REAL,    "Initial G-S voltage"),
- IOPU("temp",       VDMOS_TEMP,       IF_REAL,    "Instance temperature"),
  IOPU("dtemp",      VDMOS_DTEMP,      IF_REAL,    "Instance temperature difference"),
  IP( "ic",          VDMOS_IC,         IF_REALVEC, "Vector of D-S, G-S voltages"),
 

src/spicelib/devices/vdmos/vdmosask.c

@@ -23,9 +23,6 @@ VDMOSask(CKTcircuit *ckt, GENinstance *inst, int which, IFvalue *value,
     NG_IGNORE(select);
 
     switch(which) {
-        case VDMOS_TEMP:
-            value->rValue = here->VDMOStemp - CONSTCtoK;
-            return(OK);
         case VDMOS_DTEMP:
             value->rValue = here->VDMOSdtemp;
             return(OK);

src/spicelib/devices/vdmos/vdmosdefs.h

@@ -148,7 +148,6 @@ typedef struct sVDMOSinstance {
     int VDMOSmode;       /* device mode : 1 = normal, -1 = inverse */
 
     unsigned VDMOSoff:1;  /* non-zero to indicate device is off for dc analysis*/
-    unsigned VDMOStempGiven :1;  /* instance temperature specified */
     unsigned VDMOSdtempGiven :1;  /* instance delta temperature specified */
     unsigned VDMOSmGiven :1;
     unsigned VDMOSdNodePrimeSet :1;
@@ -498,7 +497,6 @@ enum {
     VDMOS_CG,
     VDMOS_CS,
     VDMOS_POWER,
-    VDMOS_TEMP,
     VDMOS_M,
     VDMOS_DTEMP,
     VDMOS_THERMAL,

src/spicelib/devices/vdmos/vdmosload.c

@@ -296,16 +296,18 @@ VDMOSload(GENmodel *inModel, CKTcircuit *ckt)
 
             /*  Calculate temperature dependent values for self-heating effect  */
             if (selfheat) {
-                double TempRatio = Temp / here->VDMOStemp;
-                Beta = here->VDMOStTransconductance * pow(TempRatio,model->VDMOSmu);
-                dBeta_dT = Beta * model->VDMOSmu / Temp;
-                rd0T =  here->VDMOSdrainResistance * pow(TempRatio, model->VDMOStexp0);
-                drd0T_dT = rd0T * model->VDMOStexp0 / Temp;
+                Beta = here->VDMOStTransconductance;
+                dBeta_dT = Beta * model->VDMOSmu * pow(Temp, model->VDMOSmu-1) / pow(model->VDMOStnom, model->VDMOSmu);
+                rd0T = here->VDMOSdrainResistance;
+                if (model->VDMOStexp0Given)
+                    drd0T_dT = rd0T * model->VDMOStexp0 * pow(Temp, model->VDMOStexp0-1) / pow(model->VDMOStnom, model->VDMOStexp0);
+                else
+                    drd0T_dT = rd0T * (model->VDMOStrd1 + model->VDMOStrd2*(2*model->VDMOStnom*Temp - model->VDMOStnom*model->VDMOStnom));
                 rd1T = 0.0;
                 drd1T_dT = 0.0;
                 if (model->VDMOSqsGiven) {
-                    rd1T = here->VDMOSqsResistance * pow(TempRatio, model->VDMOStexp1);
-                    drd1T_dT = rd1T * model->VDMOStexp1 / Temp;
+                    rd1T = here->VDMOSqsResistance;
+                    drd1T_dT = rd1T * model->VDMOStexp1 * pow(Temp, model->VDMOStexp1-1) / pow(model->VDMOStnom, model->VDMOStexp1);
                 }
             } else {
                 Beta = here->VDMOStTransconductance;

src/spicelib/devices/vdmos/vdmospar.c

@@ -30,10 +30,6 @@ VDMOSparam(int param, IFvalue *value, GENinstance *inst, IFvalue *select)
         scale = 1;
 
     switch (param) {
-        case VDMOS_TEMP:
-            here->VDMOStemp = value->rValue+CONSTCtoK;
-            here->VDMOStempGiven = TRUE;
-            break;
         case VDMOS_DTEMP:
             here->VDMOSdtemp = value->rValue;
             here->VDMOSdtempGiven = TRUE;

src/spicelib/devices/vdmos/vdmosset.c

@@ -304,6 +304,10 @@ VDMOSsetup(SMPmatrix *matrix, GENmodel *inModel, CKTcircuit *ckt,
                 here->VDIOconductance = 0.0;
             }
 
+            if (!here->VDMOSdtempGiven) here->VDMOSdtemp = 0.0;
+
+            here->VDMOStemp = ckt->CKTtemp + here->VDMOSdtemp;
+
             if (model->VDMOSdrainResistance > 0) {
                 if (here->VDMOSdNodePrime == 0) {
                     error = CKTmkVolt(ckt, &tmp, here->VDMOSname, "drain");

src/spicelib/devices/vdmos/vdmostemp.c

@@ -191,11 +191,6 @@ VDMOStemp(GENmodel *inModel, CKTcircuit *ckt)
         /* loop through all the instances */
         for(here=VDMOSinstances(model);here;here=VDMOSnextInstance(here)) {
 
-            if(!here->VDMOSdtempGiven) here->VDMOSdtemp = 0.0;
-
-            if(!here->VDMOStempGiven)
-                here->VDMOStemp = ckt->CKTtemp + here->VDMOSdtemp;
-
             VDMOStempUpdate(model, here, here->VDMOStemp, ckt);
 
         } /* instance */