huojinsi
Full Member level 5
Hi every one:
I am learning a schematic of OPA which is quoted from a textbook. When i simulated the open loop gain frequency curve, i found the gain frequency curve of open loop didn't degrade with frequency varying, In other words, the gain curve doesn't have -3db breakoff point when the frequency is increasing. I am very confused, because the models file contain capacitor paramter and the circuit contain compensation capacitor. Why to yield this strange phenomenon? Pls guide me! If u have a free time, pls help me simulate it! The schematic of OPA is in the attachment.Thks in advanced!
my models file is
"*FOR SPECTRE
.model MOSN NMOS
+Level= 11
*
* GENERAL PARAMETERS
*
+lmin=6.0e-7 lmax=3.0e-5
+wmin=6.0e-7 wmax=6.0e-5
+Tnom=25.0 version=3.1
+Tox=1.25E-08 Xj=1.0000000E-07
+Nch=1.3196000E+17 lln=0.7550657
+lwn=1.0000000 wln=1.7385179
+wwn=2.0000000 lint=1.6723000E-07
+ll=-1.6375242E-12 lw=0.00
+lwl=-4.0506720E-19 wint=1.2458000E-07
+wl=-1.8283731E-19 ww=-2.3537305E-20
+wwl=0.00 Mobmod=1
+binunit=2 xl=0.00
+xw=0.00 Dwg=-1.5901913E-08
+Dwb=1.4839435E-08
*
* DIODE PARAMETERS
*
+ldif=0.00 hdif=0.00
+rsh=0 rd=0
+rs=0 rsc=0
+rdc=0
*
* THRESHOLD VOLTAGE PARAMETERS
*
+Vth0=0.6929701 K1=0.8389516
+K2=-5.7840230E-02 K3=2.5218985
+Dvt0=4.7742720 Dvt1=0.8496043
+Dvt2=-0.1037025 Dvt0w=0.00
+Dvt1w=0.00 Dvt2w=0.1900000
+Nlx=0.00 W0=2.3155847E-07
+K3b=-2.6079214 Ngate=1.0000000E+30
*
* MOBILITY PARAMETERS
*
+Vsat=8.8189170E+04 Ua=-8.8038300E-10
+Ub=2.8512771E-18 Uc=3.6204920E-11
+Rdsw=1.3140129E+03 Prwb=1.8216049E-02
+Prwg=-3.5016470E-02 Wr=0.9094040
+U0=4.2317160E-02 A0=0.2826061
+Keta=-1.4081742E-02 A1=0.00
+A2=0.9900000 Ags=2.0000000E-02
+B0=4.5134230E-08 B1=-3.6182750E-07
*
* SUBTHRESHOLD CURRENT PARAMETERS
*
+Voff=-9.6546230E-02 NFactor=1.6005070
+Cit=-6.5337530E-04 Cdsc=0.00
+Cdscb=0.00 Cdscd=4.6825380E-05
+Eta0=0.1064645 Etab=-5.5450850E-02
+Dsub=0.6590825
*
* ROUT PARAMETERS
*
+Pclm=2.2878227 Pdiblc1=0.1000000
+Pdiblc2=8.7633540E-04 Pdiblcb=-0.1000000
+Drout=0.4651489 Pscbe1=4.8989800E+08
+Pscbe2=1.0000000E-20 Pvag=1.0000000
+Delta=1.0000000E-02 Alpha0=0.00
+Beta0=30.0000000
*
* TEMPERATURE EFFECTS PARAMETERS
*
+kt1=-0.3654486 kt2=-2.5749199E-02
+At=1.5000000E+04 Ute=-1.3589500
+Ua1=2.7960341E-09 Ub1=-3.4426440E-18
+Uc1=-1.8533992E-11 Kt1l=0.00
+Prt=0.00
*
* CAPACITANCE PARAMETERS
*
+Cj=0.000343 Mj=0.593
+Pb=2.55 Cjsw=2.91E-09
+Mjsw=0.362 Pbsw=0.303
+Cjswg=2E-14 Mjswg=0.33
+Pbswg=0.7 Cta=0.00105
+Ctp=-2.90E-04 Pta=-3.59E-04
+Ptp=5.06E-4 JS=1.00E-04
+JSW=0.00 N=1.0
+Xti=3.0 Cgdo=9.0035E-11
+Cgso=3.7503E-10 Cgbo=1E-12
+Capmod=3 NQSMOD=0
+Elm=5 Xpart=0
+cgsl=5.0000000E-11 cgdl=4.1552E-10
+ckappa=0.6000000 cf=0.00
+clc=8.56000E-09 cle=0.8100000
+Dlc=-5.79E-07 Dwc=1.9992E-09
+Vfbcv=-0.838282
*
*
***************************************************************
* PMOS DEVICES MODEL *
***************************************************************
* FOR SPECTRE
.model MOSP PMOS
+Level= 11
*
* GENERAL PARAMETERS
*
+lmin=6.0e-7 lmax=3.0e-5
+wmin=6.0e-7 wmax=6.0e-5
+Tnom=25.0 version=3.1
+Tox=1.25E-08 Xj=1.0000000E-07
+Nch=3.8952000E+16 lln=0.3728379
+lwn=1.0000000 wln=1.9910562
+wwn=1.3712339 lint=-7.8715000E-08
+ll=2.0611995E-10 lw=0.00
+lwl=-1.0559602E-16 wint=2.2922001E-07
+wl=-9.4221030E-22 ww=-3.9271670E-16
+wwl=0.00 Mobmod=1
+binunit=2 xl=0.00
+xw=0.00 Dwg=-1.7118449E-08
+Dwb=9.4421320E-09
*
* DIODE PARAMETERS
*
+ldif=0.00 hdif=0.00
+rsh=0 rd=0
+rs=0 rsc=0
+rdc=0
*
* THRESHOLD VOLTAGE PARAMETERS
*
+Vth0=-0.9534206 K1=0.4306269
+K2=2.4288371E-02 K3=2.8558486
+Dvt0=9.2671260 Dvt1=1.2710701
+Dvt2=-0.1255428 Dvt0w=0.00
+Dvt1w=0.00 Dvt2w=0.1900000
+Nlx=0.00 W0=-1.8608442E-07
+K3b=-0.6373694 Ngate=1.0000000E+30
*
* MOBILITY PARAMETERS
*
+Vsat=1.5532217E+05 Ua=2.3390669E-09
+Ub=2.9231469E-19 Uc=-4.1082440E-11
+Rdsw=1.2391572E+03 Prwb=-2.5805227E-02
+Prwg=-8.4016780E-03 Wr=0.8132943
+U0=2.1171642E-02 A0=0.4847234
+Keta=4.2094130E-03 A1=0.00
+A2=0.4000000 Ags=2.0000000E-02
+B0=1.5313557E-07 B1=-3.1252178E-08
*
* SUBTHRESHOLD CURRENT PARAMETERS
*
+Voff=-0.1121503 NFactor=2.0000000
+Cit=-4.0293170E-04 Cdsc=4.1957440E-04
+Cdscb=0.00 Cdscd=4.3705550E-05
+Eta0=0.2910967 Etab=-2.8794665E-02
+Dsub=0.6654378
*
* ROUT PARAMETERS
*
+Pclm=5.0000000 Pdiblc1=1.0000000E-05
+Pdiblc2=1.5418571E-03 Pdiblcb=0.1000000
+Drout=3.0000000 Pscbe1=4.8989800E+08
+Pscbe2=1.0000000E-20 Pvag=0.8505571
+Delta=1.0000000E-02 Alpha0=0.00
+Beta0=30.0000000
*
* TEMPERATURE EFFECTS PARAMETERS
*
+kt1=-0.4858726 kt2=-2.0427300E-02
+At=1.0000000E+04 Ute=-1.0726622
+Ua1=3.7500000E-09 Ub1=-6.6092640E-18
+Uc1=-7.5526270E-11 Kt1l=0.00
+Prt=0.00
*
* CAPACITANCE PARAMETERS
*
+Cj=0.000704 Mj=0.426
+Pb=0.855 Cjsw=2.81E-10
+Mjsw=0.804 Pbsw=1.53
+Cjswg=2E-14 Mjswg=0.33
+Pbswg=0.7 Cta=0.000947
+Ctp=0.00284 Pta=2.17E-03
+Ptp=5.26E-03 JS=1.00E-04
+JSW=0.00 N=1.0
+Xti=3.0 Cgdo=1.2004E-10
+Cgso=8.2544E-11 Cgbo=1E-12
+Capmod=3 NQSMOD=0
+Elm=5 Xpart=0
+cgsl=8.0000000E-13 cgdl=3.67460000E-10
+ckappa=0.6000000 cf=0.00
+clc=1.0000000E-09 cle=0.600000
+Dlc=-2.98E-07 Dwc=0
+Vfbcv=0.07944
*
"
I am learning a schematic of OPA which is quoted from a textbook. When i simulated the open loop gain frequency curve, i found the gain frequency curve of open loop didn't degrade with frequency varying, In other words, the gain curve doesn't have -3db breakoff point when the frequency is increasing. I am very confused, because the models file contain capacitor paramter and the circuit contain compensation capacitor. Why to yield this strange phenomenon? Pls guide me! If u have a free time, pls help me simulate it! The schematic of OPA is in the attachment.Thks in advanced!
my models file is
"*FOR SPECTRE
.model MOSN NMOS
+Level= 11
*
* GENERAL PARAMETERS
*
+lmin=6.0e-7 lmax=3.0e-5
+wmin=6.0e-7 wmax=6.0e-5
+Tnom=25.0 version=3.1
+Tox=1.25E-08 Xj=1.0000000E-07
+Nch=1.3196000E+17 lln=0.7550657
+lwn=1.0000000 wln=1.7385179
+wwn=2.0000000 lint=1.6723000E-07
+ll=-1.6375242E-12 lw=0.00
+lwl=-4.0506720E-19 wint=1.2458000E-07
+wl=-1.8283731E-19 ww=-2.3537305E-20
+wwl=0.00 Mobmod=1
+binunit=2 xl=0.00
+xw=0.00 Dwg=-1.5901913E-08
+Dwb=1.4839435E-08
*
* DIODE PARAMETERS
*
+ldif=0.00 hdif=0.00
+rsh=0 rd=0
+rs=0 rsc=0
+rdc=0
*
* THRESHOLD VOLTAGE PARAMETERS
*
+Vth0=0.6929701 K1=0.8389516
+K2=-5.7840230E-02 K3=2.5218985
+Dvt0=4.7742720 Dvt1=0.8496043
+Dvt2=-0.1037025 Dvt0w=0.00
+Dvt1w=0.00 Dvt2w=0.1900000
+Nlx=0.00 W0=2.3155847E-07
+K3b=-2.6079214 Ngate=1.0000000E+30
*
* MOBILITY PARAMETERS
*
+Vsat=8.8189170E+04 Ua=-8.8038300E-10
+Ub=2.8512771E-18 Uc=3.6204920E-11
+Rdsw=1.3140129E+03 Prwb=1.8216049E-02
+Prwg=-3.5016470E-02 Wr=0.9094040
+U0=4.2317160E-02 A0=0.2826061
+Keta=-1.4081742E-02 A1=0.00
+A2=0.9900000 Ags=2.0000000E-02
+B0=4.5134230E-08 B1=-3.6182750E-07
*
* SUBTHRESHOLD CURRENT PARAMETERS
*
+Voff=-9.6546230E-02 NFactor=1.6005070
+Cit=-6.5337530E-04 Cdsc=0.00
+Cdscb=0.00 Cdscd=4.6825380E-05
+Eta0=0.1064645 Etab=-5.5450850E-02
+Dsub=0.6590825
*
* ROUT PARAMETERS
*
+Pclm=2.2878227 Pdiblc1=0.1000000
+Pdiblc2=8.7633540E-04 Pdiblcb=-0.1000000
+Drout=0.4651489 Pscbe1=4.8989800E+08
+Pscbe2=1.0000000E-20 Pvag=1.0000000
+Delta=1.0000000E-02 Alpha0=0.00
+Beta0=30.0000000
*
* TEMPERATURE EFFECTS PARAMETERS
*
+kt1=-0.3654486 kt2=-2.5749199E-02
+At=1.5000000E+04 Ute=-1.3589500
+Ua1=2.7960341E-09 Ub1=-3.4426440E-18
+Uc1=-1.8533992E-11 Kt1l=0.00
+Prt=0.00
*
* CAPACITANCE PARAMETERS
*
+Cj=0.000343 Mj=0.593
+Pb=2.55 Cjsw=2.91E-09
+Mjsw=0.362 Pbsw=0.303
+Cjswg=2E-14 Mjswg=0.33
+Pbswg=0.7 Cta=0.00105
+Ctp=-2.90E-04 Pta=-3.59E-04
+Ptp=5.06E-4 JS=1.00E-04
+JSW=0.00 N=1.0
+Xti=3.0 Cgdo=9.0035E-11
+Cgso=3.7503E-10 Cgbo=1E-12
+Capmod=3 NQSMOD=0
+Elm=5 Xpart=0
+cgsl=5.0000000E-11 cgdl=4.1552E-10
+ckappa=0.6000000 cf=0.00
+clc=8.56000E-09 cle=0.8100000
+Dlc=-5.79E-07 Dwc=1.9992E-09
+Vfbcv=-0.838282
*
*
***************************************************************
* PMOS DEVICES MODEL *
***************************************************************
* FOR SPECTRE
.model MOSP PMOS
+Level= 11
*
* GENERAL PARAMETERS
*
+lmin=6.0e-7 lmax=3.0e-5
+wmin=6.0e-7 wmax=6.0e-5
+Tnom=25.0 version=3.1
+Tox=1.25E-08 Xj=1.0000000E-07
+Nch=3.8952000E+16 lln=0.3728379
+lwn=1.0000000 wln=1.9910562
+wwn=1.3712339 lint=-7.8715000E-08
+ll=2.0611995E-10 lw=0.00
+lwl=-1.0559602E-16 wint=2.2922001E-07
+wl=-9.4221030E-22 ww=-3.9271670E-16
+wwl=0.00 Mobmod=1
+binunit=2 xl=0.00
+xw=0.00 Dwg=-1.7118449E-08
+Dwb=9.4421320E-09
*
* DIODE PARAMETERS
*
+ldif=0.00 hdif=0.00
+rsh=0 rd=0
+rs=0 rsc=0
+rdc=0
*
* THRESHOLD VOLTAGE PARAMETERS
*
+Vth0=-0.9534206 K1=0.4306269
+K2=2.4288371E-02 K3=2.8558486
+Dvt0=9.2671260 Dvt1=1.2710701
+Dvt2=-0.1255428 Dvt0w=0.00
+Dvt1w=0.00 Dvt2w=0.1900000
+Nlx=0.00 W0=-1.8608442E-07
+K3b=-0.6373694 Ngate=1.0000000E+30
*
* MOBILITY PARAMETERS
*
+Vsat=1.5532217E+05 Ua=2.3390669E-09
+Ub=2.9231469E-19 Uc=-4.1082440E-11
+Rdsw=1.2391572E+03 Prwb=-2.5805227E-02
+Prwg=-8.4016780E-03 Wr=0.8132943
+U0=2.1171642E-02 A0=0.4847234
+Keta=4.2094130E-03 A1=0.00
+A2=0.4000000 Ags=2.0000000E-02
+B0=1.5313557E-07 B1=-3.1252178E-08
*
* SUBTHRESHOLD CURRENT PARAMETERS
*
+Voff=-0.1121503 NFactor=2.0000000
+Cit=-4.0293170E-04 Cdsc=4.1957440E-04
+Cdscb=0.00 Cdscd=4.3705550E-05
+Eta0=0.2910967 Etab=-2.8794665E-02
+Dsub=0.6654378
*
* ROUT PARAMETERS
*
+Pclm=5.0000000 Pdiblc1=1.0000000E-05
+Pdiblc2=1.5418571E-03 Pdiblcb=0.1000000
+Drout=3.0000000 Pscbe1=4.8989800E+08
+Pscbe2=1.0000000E-20 Pvag=0.8505571
+Delta=1.0000000E-02 Alpha0=0.00
+Beta0=30.0000000
*
* TEMPERATURE EFFECTS PARAMETERS
*
+kt1=-0.4858726 kt2=-2.0427300E-02
+At=1.0000000E+04 Ute=-1.0726622
+Ua1=3.7500000E-09 Ub1=-6.6092640E-18
+Uc1=-7.5526270E-11 Kt1l=0.00
+Prt=0.00
*
* CAPACITANCE PARAMETERS
*
+Cj=0.000704 Mj=0.426
+Pb=0.855 Cjsw=2.81E-10
+Mjsw=0.804 Pbsw=1.53
+Cjswg=2E-14 Mjswg=0.33
+Pbswg=0.7 Cta=0.000947
+Ctp=0.00284 Pta=2.17E-03
+Ptp=5.26E-03 JS=1.00E-04
+JSW=0.00 N=1.0
+Xti=3.0 Cgdo=1.2004E-10
+Cgso=8.2544E-11 Cgbo=1E-12
+Capmod=3 NQSMOD=0
+Elm=5 Xpart=0
+cgsl=8.0000000E-13 cgdl=3.67460000E-10
+ckappa=0.6000000 cf=0.00
+clc=1.0000000E-09 cle=0.600000
+Dlc=-2.98E-07 Dwc=0
+Vfbcv=0.07944
*
"