make breakdown voltage internally always positive

src/spicelib/devices/vdmos/vdmosload.c

@@ -677,7 +677,7 @@ bypass :
             gspr = here->VDIOtConductance;
             vte = model->VDMOSDn * vt;
             vtebrk = model->VDIObrkdEmissionCoeff * vt;
-            vbrknp = model->VDMOStype * here->VDIOtBrkdwnV;
+            vbrknp = here->VDIOtBrkdwnV;
 
             Check = 1;
             if (ckt->CKTmode & MODEINITSMSIG) {

src/spicelib/devices/vdmos/vdmostemp.c

@@ -252,7 +252,7 @@ VDMOStemp(GENmodel *inModel, CKTcircuit *ckt)
             * temperature adjusted basic parameters */
             if (model->VDMOSDbvGiven) {
                 /* tlev == 0 */
-                tBreakdownVoltage = model->VDMOSDbv;
+                tBreakdownVoltage = fabs(model->VDMOSDbv);
 
                 cbv = model->VDMOSDibv;