Ltspice ? about warnings in a log file. - Page 1
Forum section: electronics / projects

author: rolloman
author_rank: Newbie
timestamp: July 07, 2017, 12:46:32 pm
content: My simulation runs fine but I get this text shown below that pops up after each run ends. It started when I added the part that I have included below also using the .include. Is this something I need to resolve, or can it be ignored. I am kinda new at Ltspice so don't know what to expect sometimes with what it does. Thanks to anyone that can help.Circuit: * C:\Users\owner\Documents\LTspiceXVII\Custom Amp.ascError on line 1747 : .model m6:bsim3 nmos (level=7 version=3.1 mobmod=3 capmod=2 paramchk=1 nqsmod=0 tox=970e-10 xj=1.4e-6 nch=1.7e17 ua=1.6e-9 u0=700 vsat=1.0e5 drout=3.0 pvag=5 delta=0.10 pscbe2=0 rsh=1.0e-3 pdiblc2=1e-7 vth0=3.50 voff=-0.1 nfactor=1.1 lint=5.90e-7 dlc=5.90e-7 fc=0.5 cgso=1.12e-9 cgsl=0 cgdo=1.05e-14 cgdl=1.68e-9 cj=0 cf=0 ckappa=0.20 kt1=-2.07 kt2=0 ua1=1.02e-9 nj=10 )* Unrecognized parameter "fc" -- ignoredError on line 1747 : .model m5:bsim3 nmos (level=7 version=3.1 mobmod=3 capmod=2 paramchk=1 nqsmod=0 tox=970e-10 xj=1.4e-6 nch=1.7e17 ua=1.6e-9 u0=700 vsat=1.0e5 drout=3.0 pvag=5 delta=0.10 pscbe2=0 rsh=1.0e-3 pdiblc2=1e-7 vth0=3.50 voff=-0.1 nfactor=1.1 lint=5.90e-7 dlc=5.90e-7 fc=0.5 cgso=1.12e-9 cgsl=0 cgdo=1.05e-14 cgdl=1.68e-9 cj=0 cf=0 ckappa=0.20 kt1=-2.07 kt2=0 ua1=1.02e-9 nj=10 )* Unrecognized parameter "fc" -- ignoredWarning: Pscbe2 = 0 is not positive.Warning: Pd = 0 is less than W.Warning: Ps = 0 is less than W.Warning: Pscbe2 = 0 is not positive.Warning: Pd = 0 is less than W.Warning: Ps = 0 is less than W.Instance "m:m3:1": Length shorter than recommended for a level 1 MOSFET.Instance "m:m3:1": Width narrower than recommended for a level 1 MOSFET.Per .tran options, skipping operating point for transient analysis.Heightened Def Con from 0.589734 to 0.589734Date: Fri Jul 07 08:38:35 2017Total elapsed time: 36.055 seconds.tnom = 27temp = 27method = modified traptotiter = 236482traniter = 236482tranpoints = 62603accept = 46734rejected = 15870matrix size = 262fillins = 428solver = NormalMatrix Compiler1: 44.92 KB object code size 23.9/41.1/[8.5]Matrix Compiler2: 29.26 KB object code size 7.3/18.3/[4.6]Heres the part file that caused this error log when I added it with a .include statement.**************** Power Discrete MOSFET Electrical Circuit Model ******************* Product Name: FQH8N100C** 1000V N-Channel MOSFET and TO-247** Model Type: BSIM3V3**-------------------------------------------------------------------------------.SUBCKT FQH8N100C 2 1 3*Nom Temp=25 deg CDbody 7 5 DbodyMODDbreak 5 11 DbreakMODEbreak 11 7 17 7 1000Lgate 1 9 1.125e-9Ldrain 2 5 1.440e-9Lsource 3 7 9.106e-10RLgate 1 9 11.25RLdrain 2 5 14.4RLsource 3 7 9.11Rgate 9 6 0.5It 7 17 1Rbreak 17 7 RbreakMOD 1.MODEL RbreakMOD RES (TC1=1.18e-3 TC2=-1.15e-6).MODEL DbodyMOD D (IS=6.45e-9 N=1.5 RS=4.44e-3 TRS1=3.8e-3 TRS2=5.8e-6+ CJO=1.76e-09 M=0.53 VJ=0.45 TT=1.09e-6 XTI=3 EG=1.154).MODEL DbreakMOD D (RS=100e-3 TRS1=1.0e-3 TRS2=5.0e-6)Rdrain 5 16 RdrainMOD 1.2.MODEL RdrainMOD RES (TC1=8.8e-3 TC2=1.66e-5)M_BSIM3 16 6 7 7 Bsim3 W=1.08 L=2.0e-6 NRS=1.MODEL Bsim3 NMOS (LEVEL=7 VERSION=3.1 MOBMOD=3 CAPMOD=2 PARAMCHK=1 NQSMOD=0+ TOX=970e-10 XJ=1.4e-6 NCH=1.7e17 UA=1.6e-9+ U0=700 VSAT=1.0e5 DROUT=3.0 PVAG=5+ DELTA=0.10 PSCBE2=0 RSH=1.0e-3 PDIBLC2=1e-7+ VTH0=3.50 VOFF=-0.1 NFACTOR=1.1+ LINT=5.90e-7 DLC=5.90e-7 FC=0.5+ CGSO=1.12e-9 CGSL=0 CGDO=1.05e-14+ CGDL=1.68e-9 CJ=0 CF=0+ CKAPPA=0.20 KT1=-2.07 KT2=0+ UA1=1.02e-9 NJ=10 ).ENDS******************** Power Discrete MOSFET Thermal Model ************************** 1000V N-Channel MOSFET and TO-247**-------------------------------------------------------------------------------.SUBCKT FQH8N100C_Thermal TH TLCTHERM1 TH 6 1.12e-5CTHERM2 6 5 1.53e-3CTHERM3 5 4 1.82e-2CTHERM4 4 3 6.45e-2CTHERM5 3 2 8.12e-2CTHERM6 2 TL 5.21e-1RTHERM1 TH 6 4.00e-4RTHERM2 6 5 8.10e-3RTHERM3 5 4 3.40e-2RTHERM4 4 3 9.10e-2RTHERM5 3 2 1.02e-1RTHERM6 2 TL 3.24e-1.ENDS FQH8N100C_Thermal**-------------------------------------------------------------------------------** Creation: Jan.-05-2010 Rev.: 0.0** Fairchild Semiconductor

author: UselessUser
author_rank: Newbie
timestamp: December 06, 2017, 01:46:13 pm
content: I got the same for Pscbe2, Pd, Ps, and Fc when using the Fairchild model for a BSS138W mosfet in LTSpice. I just want to use the mosfet for basic switching and don't have time to become an expert in modelling each one I use. It seems to run just fine, but over what region would results be valid?OnSemi Tech support gave me this.This model was made by Fairchild before the merger. In general:FC is the depletion capacitance coefficient and will probably have little effect on the model as long as it is within the normal range of .1 to .8 (typical is .5)Fromhttps://www.seas.upenn.edu/~jan/spice/PSpice_ReferenceguideOrCAD.pdfPD and PSThe drain and source diffusion perimeters. Their default value is 0.PSCBE2 second substrate current body effect coefficient m/V 1.0E-5But none of this helps me to know the region in which the model is valid.