Enhance the SOA (safe operating area) operations

Parameters id_max, pd_max and te_max have been added
for current, power, and temperature to the already existing
fv_max and bv_max (max forward and backward volteges).

src/spicelib/devices/dio/dio.c

@@ -108,11 +108,16 @@ IFparm DIOmPTable[] = { /* model parameters */
  IOPR( "ib", DIO_MOD_IBV, IF_REAL, "Current at reverse breakdown voltage"),
  IOP( "tcv", DIO_MOD_TCV, IF_REAL, "Reverse breakdown voltage temperature coefficient"),
  OPU( "cond", DIO_MOD_COND,IF_REAL, "Ohmic conductance"),
+ IOP( "isr",  DIO_MOD_ISR,  IF_REAL, "Recombination saturation current"),
+ IOP( "nr",   DIO_MOD_NR,   IF_REAL, "Recombination current emission coefficient"),
 
+ /* SOA parameters */
  IOP( "fv_max",   DIO_MOD_FV_MAX,  IF_REAL, "maximum voltage in forward direction"),
  IOP( "bv_max",   DIO_MOD_BV_MAX,  IF_REAL, "maximum voltage in reverse direction"),
- IOP( "isr",  DIO_MOD_ISR,  IF_REAL, "Recombination saturation current"),
- IOP( "nr",   DIO_MOD_NR,   IF_REAL, "Recombination current emission coefficient"),
+ IOP( "id_max",   DIO_MOD_ID_MAX,  IF_REAL, "maximum current"),
+ IOP( "te_max",   DIO_MOD_TE_MAX,  IF_REAL, "temperature"),
+ IOP( "pd_max",   DIO_MOD_PD_MAX,  IF_REAL, "maximum power dissipation"),
+
 /* self heating */
  IOP("rth0",  DIO_MOD_RTH0,  IF_REAL, "Self-heating thermal resistance"),
  IOP("cth0",  DIO_MOD_CTH0,  IF_REAL, "Self-heating thermal capacitance"),

src/spicelib/devices/dio/diodefs.h

@@ -275,6 +275,9 @@ typedef struct sDIOmodel {       /* model structure for a diode */
     unsigned DIOtunEGcorrectionFactorGiven : 1;
     unsigned DIOfv_maxGiven : 1;
     unsigned DIObv_maxGiven : 1;
+    unsigned DIOid_maxGiven : 1;
+    unsigned DIOpd_maxGiven : 1;
+    unsigned DIOte_maxGiven : 1;
     unsigned DIOrecSatCurGiven : 1;
     unsigned DIOrecEmissionCoeffGiven : 1;
 
@@ -342,6 +345,9 @@ typedef struct sDIOmodel {       /* model structure for a diode */
     double DIOtunEGcorrectionFactor; /* EG correction factor for tunneling (KEG) */
     double DIOfv_max; /* maximum voltage in forward direction */
     double DIObv_max; /* maximum voltage in reverse direction */
+    double DIOid_max; /* maximum current */
+    double DIOpd_max; /* maximum power dissipation */
+    double DIOte_max; /* maximum temperature */
     double DIOrecSatCur; /* Recombination saturation current */
     double DIOrecEmissionCoeff; /* Recombination emission coefficient */
 
@@ -442,6 +448,9 @@ enum {
     DIO_MOD_KEG,
     DIO_MOD_FV_MAX,
     DIO_MOD_BV_MAX,
+    DIO_MOD_ID_MAX,
+    DIO_MOD_TE_MAX,
+    DIO_MOD_PD_MAX,
     DIO_MOD_ISR,
     DIO_MOD_NR,
     DIO_MOD_RTH0,

src/spicelib/devices/dio/diomask.c

@@ -172,6 +172,15 @@ DIOmAsk (CKTcircuit *ckt, GENmodel *inModel, int which, IFvalue *value)
         case DIO_MOD_BV_MAX:
             value->rValue = model->DIObv_max;
             return(OK);
+        case DIO_MOD_ID_MAX:
+            value->rValue = model->DIOid_max;
+            return(OK);
+        case DIO_MOD_PD_MAX:
+            value->rValue = model->DIOpd_max;
+            return(OK);
+        case DIO_MOD_TE_MAX:
+            value->rValue = model->DIOte_max;
+            return(OK);
         case DIO_MOD_ISR:
             value->rValue = model->DIOrecSatCur;
             return(OK);

src/spicelib/devices/dio/diompar.c

@@ -209,6 +209,18 @@ DIOmParam(int param, IFvalue *value, GENmodel *inModel)
             model->DIObv_max = value->rValue;
             model->DIObv_maxGiven = TRUE;
             break;
+        case DIO_MOD_ID_MAX:
+            model->DIOid_max = value->rValue;
+            model->DIOid_maxGiven = TRUE;
+            break;
+        case DIO_MOD_PD_MAX:
+            model->DIOpd_max = value->rValue;
+            model->DIOpd_maxGiven = TRUE;
+            break;
+        case DIO_MOD_TE_MAX:
+            model->DIOte_max = value->rValue;
+            model->DIOte_maxGiven = TRUE;
+            break;
         case DIO_MOD_ISR:
             model->DIOrecSatCur = value->rValue;
             model->DIOrecSatCurGiven = TRUE;

src/spicelib/devices/dio/diosetup.c

@@ -164,6 +164,15 @@ DIOsetup(SMPmatrix *matrix, GENmodel *inModel, CKTcircuit *ckt, int *states)
         if(!model->DIObv_maxGiven) {
             model->DIObv_max = 1e99;
         }
+        if(!model->DIOid_maxGiven) {
+            model->DIOid_max = 1e99;
+        }
+        if(!model->DIOpd_maxGiven) {
+            model->DIOpd_max = 1e99;
+        }
+        if(!model->DIOte_maxGiven) {
+            model->DIOte_max = 1e99;
+        }
         if(!model->DIOrecEmissionCoeffGiven) {
             model->DIOrecEmissionCoeff = 1;
         }

src/spicelib/devices/dio/diosoachk.c

@@ -18,12 +18,18 @@ DIOsoaCheck(CKTcircuit *ckt, GENmodel *inModel)
     DIOmodel *model = (DIOmodel *) inModel;
     DIOinstance *here;
     double vd;  /* current diode voltage */
+    double id;  /* current diode current */
+    double pd;  /* current diode power */
+    double te;  /* current diode temperature */
     int maxwarns;
-    static int warns_fv = 0, warns_bv = 0;
+    static int warns_fv = 0, warns_bv = 0, warns_id = 0, warns_pd = 0, warns_te = 0;
 
     if (!ckt) {
         warns_fv = 0;
         warns_bv = 0;
+        warns_id = 0;
+        warns_pd = 0;
+        warns_te = 0;
         return OK;
     }
 
@@ -52,6 +58,37 @@ DIOsoaCheck(CKTcircuit *ckt, GENmodel *inModel)
                     warns_bv++;
                 }
 
+            id = fabs(*(ckt->CKTstate0 + here->DIOcurrent));
+            if (id > fabs(model->DIOid_max))
+                if (warns_id < maxwarns) {
+                    soa_printf(ckt, (GENinstance*) here,
+                               "Id=%g has exceeded Id_max=%g\n",
+                               id, model->DIOid_max);
+                    warns_id++;
+                }
+
+
+            pd = fabs(*(ckt->CKTstate0 + here->DIOcurrent) *
+                      *(ckt->CKTstate0 + here->DIOvoltage) +
+                      *(ckt->CKTstate0 + here->DIOcurrent) *
+                      *(ckt->CKTstate0 + here->DIOcurrent) / here->DIOtConductance);
+            if (pd > fabs(model->DIOpd_max))
+                if (warns_pd < maxwarns) {
+                    soa_printf(ckt, (GENinstance*) here,
+                               "Pd=%g has exceeded Pd_max=%g\n",
+                               pd, model->DIOpd_max);
+                    warns_pd++;
+                }
+
+            te = here->DIOtemp - CONSTCtoK;
+            if (te > model->DIOte_max)
+                if (warns_te < maxwarns) {
+                    soa_printf(ckt, (GENinstance*) here,
+                               "Te=%g has exceeded te_max=%g\n",
+                               te, model->DIOte_max);
+                    warns_te++;
+                }
+
         }
 
     }