From 10f4eeed4a17ea5904b64080670940638066b474 Mon Sep 17 00:00:00 2001
From: dwarning <dwarning>
Date: Mon, 28 Jul 2025 00:07:07 +0200
Subject: [PATCH] diode needs both current components (bottom and sidewall) for
 Vcrit and breakdown voltage calculation

---
 src/spicelib/devices/dio/diotemp.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/spicelib/devices/dio/diotemp.c b/src/spicelib/devices/dio/diotemp.c
index c49d77cc9..30a47405b 100644
--- a/src/spicelib/devices/dio/diotemp.c
+++ b/src/spicelib/devices/dio/diotemp.c
@@ -196,7 +196,8 @@ void DIOtempUpdate(DIOmodel *inModel, DIOinstance *here, double Temp, CKTcircuit
     here->DIOtDepSWCap=model->DIOdepletionSWcapCoeff*
             here->DIOtJctSWPot;
     /* and Vcrit */
-    here->DIOtVcrit = vte * log(vte/(CONSTroot2*here->DIOtSatCur));
+    double totalSatCur = here->DIOtSatCur + here->DIOtSatSWCur;
+    here->DIOtVcrit = vte * log(vte/(CONSTroot2*totalSatCur));
 
     /* and now to compute the breakdown voltage, again, using
      * temperature adjusted basic parameters */
@@ -211,9 +212,9 @@ void DIOtempUpdate(DIOmodel *inModel, DIOinstance *here, double Temp, CKTcircuit
         } else { /* level=3 */
             cbv = model->DIObreakdownCurrent * here->DIOarea * here->DIOm;
         }
-        if (cbv < here->DIOtSatCur * tBreakdownVoltage/vt) {
+        if (cbv < totalSatCur * tBreakdownVoltage/vt) {
 #ifdef TRACE
-            cbv=here->DIOtSatCur * tBreakdownVoltage/vt;
+            cbv=totalSatCur * tBreakdownVoltage/vt;
             SPfrontEnd->IFerrorf (ERR_WARNING, "%s: breakdown current increased to %g to resolve", here->DIOname, cbv);
             SPfrontEnd->IFerrorf (ERR_WARNING,
             "incompatibility with specified saturation current");
@@ -222,11 +223,11 @@ void DIOtempUpdate(DIOmodel *inModel, DIOinstance *here, double Temp, CKTcircuit
         } else {
             tol=ckt->CKTreltol*cbv;
             xbv=tBreakdownVoltage-model->DIObrkdEmissionCoeff*vt*log(1+cbv/
-                    (here->DIOtSatCur));
+                    totalSatCur);
             for(iter=0 ; iter < 25 ; iter++) {
                 xbv=tBreakdownVoltage-model->DIObrkdEmissionCoeff*vt*log(cbv/
-                        (here->DIOtSatCur)+1-xbv/vt);
-                xcbv=here->DIOtSatCur *
+                        totalSatCur+1-xbv/vt);
+                xcbv=totalSatCur *
                      (exp((tBreakdownVoltage-xbv)/(model->DIObrkdEmissionCoeff*vt))-1+xbv/vt);
                 if (fabs(xcbv-cbv) <= tol) goto matched;
             }