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Simulators >> Circuit Simulators >> how to plot op parameter curve in hspice?
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Message started by microant on Apr 18^th, 2005, 7:20pm

Title: how to plot op parameter curve in hspice?
Post by microant on Apr 18^th, 2005, 7:20pm

Hi everyone, I meet a problem with Avanti Hspice. I want to plot the curve of MOSFET operation point parameter such as gm,cgs,cgtot etc when i run a DC parameter sweep. but it seem that hspice didn't have this function, could anyone give me some advise? thanks and best regrads
microant ???

Title: Re: how to plot op parameter curve in hspice?
Post by 020170 on Apr 21^st, 2005, 4:56pm

sorry. i don't know cgs, cgtot. but if you want to know gm in saturation region, I can help you

in saturation, gm = root( 2 * K' * W/L * Idsat )

I wish that it was helpful

Title: Re: how to plot op parameter curve in hspice?
Post by Andrew Beckett on Apr 21^st, 2005, 9:45pm

I remember from many years ago that this was done with the element access functions LVnn() and LXnn() wher nn was a number which determines which parameter to output.

This is covered in the HSPICE manual, I'm sure (it was 10 years ago when I used HSPICE, so I'm sure it is now).

Regards,

Andrew.

Title: Re: how to plot op parameter curve in hspice?
Post by James on Apr 22^nd, 2005, 7:15am

Plotting Variables

Use this template to plot internal variables, such as:

i(mn1) i1, i2, i3, or i4 can specify the true branch currents, for
each transistor node.

LV18(mn6) Total gate capacitance (C-V plot).

LX7(mn1) GM gate transconductance. (LX8 specifies GDS, and LX9
specifies GMB).

Title: Re: how to plot op parameter curve in hspice?
Post by James on Apr 22^nd, 2005, 7:22am

Here is an example from Hspice user-guide

MOS I-V and C-V Plot Example Input File
*FILE: MOSIVCV.SP IDS, VGS, CV AND GM PLOTS
.OPTION SCALE=1U DCCAP
.DC VDDN 0 5.0 .1 $VBBN 0 -3 -3 sweep supplies
.PARAM ww=8 LL=2
$ ids-vds curves
.GRAPH 'I_VG=1' =I(MN1) 'I_VG=2' =I(MN2) 'I_VG=3' =I(MN3)
+ 'I_VG=4' =I(MN4)
.GRAPH 'I_VG=-1'=I(MP1) 'I_VG=-2'=I(MP2) 'I_VG=-3'=I(MP3)
+ 'I_VG=-4'=I(MP4)
$ ids-VGs curves
.GRAPH 'I_VD=.5'=I(MN6) 'I_VD=-.5'=I(MP6)
$ gate caps (cgs+cgd+cgb)
.GRAPH 'CG-TOT_N'=LX18(MN6) 'CG-TOT_P'= LX18(MP6)
$ gm
.GRAPH 'GM_N'=LX7(MN6) 'GM_P'=LX7(MP6)
VDDN vdd_n gnd 5.0
VBBN vbb_n gnd 0.0
EPD vdd_p gnd vdd_n gnd -1 $ reflect vdd for P devices
EPB vbb_p gnd vbb_n gnd -1 $ reflect vbb for P devices
V1 vg1 gnd 1
V2 vg2 gnd 2
V3 vg3 gnd 3
V4 vg4 gnd 4
V5 vddlow_n gnd .5
V-1 vg-1 gnd -1
V-2 vg-2 gnd -2
V-3 vg-3 gnd -3
V-4 vg-4 gnd -4
V-5 vddlow_p gnd -.5
MN1 vdd_n vg1 gnd vbb_n N W=ww L=LL
MN2 vdd_n vg2 gnd vbb_n N W=ww L=LL
MN3 vdd_n vg3 gnd vbb_n N W=ww L=LL
MN4 vdd_n vg4 gnd vbb_n N W=ww L=LL
MP1 gnd vg-1 vdd_p vbb_p P W=ww L=LL
MP2 gnd vg-2 vdd_p vbb_p P W=ww L=LL
MP3 gnd vg-3 vdd_p vbb_p P W=ww L=LL
MP4 gnd vg-4 vdd_p vbb_p P W=ww L=LL
MN6 vddlow_n vdd_n gnd vbb_n N W=ww L=LL
MP6 gnd vdd_p vddlow_p vbb_p P W=ww L=LL
.MODEL N NMOS LEVEL=3 VTO=0.7 UO=500 KAPPA=.25 ETA=.01
+ THETA=.04 VMAX=2E5 NSUB=9E16 TOX=400 KP=30U GAMMA=1.5
+ PB=0.6 JS=.1M XJ=0.5U LD=0.1U NFS=1E11 NSS=2E10
+ RSH=80 CJ=.3M MJ=0.5 CJSW=.1N MJSW=0.3 acm=2 capop=4
.MODEL P PMOS LEVEL=3 VTO=-0.8 UO=150 KAPPA=.25 KP=15U
+ ETA=.015 THETA=.04 VMAX=5E4 NSUB=1.8E16 TOX=400 GAMMA=.67
+ PB=0.6 JS=.1M XJ=0.5U LD=0.15U NFS=1E11 NSS=2E10
+ RSH=80 CJ=.3M MJ=0.5 CJSW=.1N MJSW=0.3 acm=2 capop=4
.END

Title: Re: how to plot op parameter curve in hspice?
Post by microant on Apr 24^th, 2005, 7:51pm

:D thanks for James and Andrew, i have plot it! i use the .meas statement and the ac analysis to plot it.
**single MOS performance test
.PARAM vinp=1 ibias=1u vcc=5
.PARAM vg1=1 vd1=2
.OP all
.AC dec 2 100 1k sweep data=corner2
.DATA corner2
tem
-40
25
60
125
.ENDDATA
*** output
***AC small-param
.MEAS AC GM find lx7(MN1) at=1k
.MEAS AC GDS find lx8(MN1) at=1k
.MEAS AC GMB find lx9(MN1) at=1k
.MEAS AC VTH find lv9(MN1) at=1k
.MEAS AC VDSAT find lv10(MN1) at=1k

*** voltage
.MEAS AC VGS find lx2(MN1) at=1k

*** capacitance at each terminal

.MEAS AC Cgtot find lx18(MN1) at=1k
.MEAS AC Cgd find lx19(MN1) at=1k
.MEAS AC Cgs find lx20(MN1) at=1k
.MEAS AC Cbg find lx21(MN1) at=1k
.MEAS AC Cbd find lx22(MN1) at=1k
.MEAS AC Cbs find lx23(MN1) at=1k
.MEAS AC Cdtot find lx33(MN1) at=1k
.MEAS AC Cdg find lx32(MN1) at=1k
.MEAS AC Cds find lx34(MN1) at=1k
.MEAS AC Cstot param='-Cgs-Cbs-Cds'
.MEAS AC Cbtot param='-Cbg-Cbs-Cbd'

*** netlist ***
MN1 VD1 VG1 0 0 nch l=4u w=2u m=1
MN2 VG2 VG2 0 0 nch l=4u w=2u m=1
I1 VCC VG2 dc ibias
V1 VCC 0 dc vcc
VG1 VG1 0 dc vg1 ac 1
VD1 VD1 0 dc vd1

best regard
microant