bharat_tangudu
Member level 1
I am trying to simulate the balanced OTA in HSPICE.
I took one paper as a reference for transistor parameters and bias current, etc. paper can be downloaded from this link https://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5746529&tag=1
Though i followed that paper, i was not getting the proper DC characteristics which is shifting toward 1st quadrant. I tried all the possible ways to shift the curve. But i was not able to solve the problem. Can someone correct me in solving this problem either by modifying the netlist if there is any mistake in that or by providing some material to clear this problem????
I am attaching the schematic of balanced OTA structure and its DC characteristics.
Also, I am copying the code here
**broken link removed**
**broken link removed**
I am new to the analog area and i really want to work in analog circuits. Please help me in solving this issue.
I took one paper as a reference for transistor parameters and bias current, etc. paper can be downloaded from this link https://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5746529&tag=1
Though i followed that paper, i was not getting the proper DC characteristics which is shifting toward 1st quadrant. I tried all the possible ways to shift the curve. But i was not able to solve the problem. Can someone correct me in solving this problem either by modifying the netlist if there is any mistake in that or by providing some material to clear this problem????
I am attaching the schematic of balanced OTA structure and its DC characteristics.
Also, I am copying the code here
**broken link removed**
**broken link removed**
Code:
----------------------------------------
Balance OTA
M1 vg4 vin+ 4 0 nmos l=0.2u w=20u
M2 vg3 vin- 4 0 nmos l=0.2u w=20u
M3 vg3 vg3 1 1 pmos l=0.2u w=15u
M4 vg4 vg4 1 1 pmos l=0.2u w=15u
M5 3 vg3 1 1 pmos l=0.2u w=15u
M6 5 vg4 1 1 pmos l=0.2u w=15u
M7 3 3 0 0 nmos l=1u w=5u
M8 5 3 0 0 nmos l=1u w=5u
M9 2 2 0 0 nmos l=1u w=15u
M10 4 2 0 0 nmos l=1u w=15u
Ib 1 2 dc 40uA
Vnull 5 0 dc 0v
Vdd 1 0 dc 1.8V
Vi1 vin+ 0 dc 0v sin(0v 100mv 10khz)
Vi2 vin- 0 dc 0.9v sin(0v 50mv 10khz)
.dc Vi1 -1 1 0.001
.op
.option post
.option nomod
.probe
.end
------------------------------------
* Predictive Technology Model Beta Version
* 180nm NMOS SPICE Parametersv (normal one)
*
.model NMOS NMOS
+Level = 49
+Lint = 4.e-08 Tox = 4.e-09
+Vth0 = 0.3999 Rdsw = 250
+lmin=1.8e-7 lmax=1.8e-7 wmin=1.8e-7 wmax=1.0e-4 Tref=27.0 version =3.1
+Xj= 6.0000000E-08 Nch= 5.9500000E+17
+lln= 1.0000000 lwn= 1.0000000 wln= 0.00
+wwn= 0.00 ll= 0.00
+lw= 0.00 lwl= 0.00 wint= 0.00
+wl= 0.00 ww= 0.00 wwl= 0.00
+Mobmod= 1 binunit= 2 xl= 0
+xw= 0 binflag= 0
+Dwg= 0.00 Dwb= 0.00
+K1= 0.5613000 K2= 1.0000000E-02
+K3= 0.00 Dvt0= 8.0000000 Dvt1= 0.7500000
+Dvt2= 8.0000000E-03 Dvt0w= 0.00 Dvt1w= 0.00
+Dvt2w= 0.00 Nlx= 1.6500000E-07 W0= 0.00
+K3b= 0.00 Ngate= 5.0000000E+20
+Vsat= 1.3800000E+05 Ua= -7.0000000E-10 Ub= 3.5000000E-18
+Uc= -5.2500000E-11 Prwb= 0.00
+Prwg= 0.00 Wr= 1.0000000 U0= 3.5000000E-02
+A0= 1.1000000 Keta= 4.0000000E-02 A1= 0.00
+A2= 1.0000000 Ags= -1.0000000E-02 B0= 0.00
+B1= 0.00
+Voff= -0.12350000 NFactor= 0.9000000 Cit= 0.00
+Cdsc= 0.00 Cdscb= 0.00 Cdscd= 0.00
+Eta0= 0.2200000 Etab= 0.00 Dsub= 0.8000000
+Pclm= 5.0000000E-02 Pdiblc1= 1.2000000E-02 Pdiblc2= 7.5000000E-03
+Pdiblcb= -1.3500000E-02 Drout= 1.7999999E-02 Pscbe1= 8.6600000E+08
+Pscbe2= 1.0000000E-20 Pvag= -0.2800000 Delta= 1.0000000E-02
+Alpha0= 0.00 Beta0= 30.0000000
+kt1= -0.3700000 kt2= -4.0000000E-02 At= 5.5000000E+04
+Ute= -1.4800000 Ua1= 9.5829000E-10 Ub1= -3.3473000E-19
+Uc1= 0.00 Kt1l= 4.0000000E-09 Prt= 0.00
+Cj= 0.00365 Mj= 0.54 Pb= 0.982
+Cjsw= 7.9E-10 Mjsw= 0.31 Php= 0.841
+Cta= 0 Ctp= 0 Pta= 0
+Ptp= 0 JS=1.50E-08 JSW=2.50E-13
+N=1.0 Xti=3.0 Cgdo=2.786E-10
+Cgso=2.786E-10 Cgbo=0.0E+00 Capmod= 2
+NQSMOD= 0 Elm= 5 Xpart= 1
+Cgsl= 1.6E-10 Cgdl= 1.6E-10 Ckappa= 2.886
+Cf= 1.069e-10 Clc= 0.0000001 Cle= 0.6
+Dlc= 4E-08 Dwc= 0 Vfbcv= -1
*
* Predictive Technology Model Beta Version
* 180nm PMOS SPICE Parametersv (normal one)
*
.model PMOS PMOS
+Level = 49
+Lint = 3.e-08 Tox = 4.2e-09
+Vth0 = -0.42 Rdsw = 450
+lmin=1.8e-7 lmax=1.8e-7 wmin=1.8e-7 wmax=1.0e-4 Tref=27.0 version =3.1
+Xj= 7.0000000E-08 Nch= 5.9200000E+17
+lln= 1.0000000 lwn= 1.0000000 wln= 0.00
+wwn= 0.00 ll= 0.00
+lw= 0.00 lwl= 0.00 wint= 0.00
+wl= 0.00 ww= 0.00 wwl= 0.00
+Mobmod= 1 binunit= 2 xl= 0.00
+xw= 0.00
+binflag= 0 Dwg= 0.00 Dwb= 0.00
+ACM= 0 ldif=0.00 hdif=0.00
+rsh= 0 rd= 0 rs= 0
+rsc= 0 rdc= 0
+K1= 0.5560000 K2= 0.00
+K3= 0.00 Dvt0= 11.2000000 Dvt1= 0.7200000
+Dvt2= -1.0000000E-02 Dvt0w= 0.00 Dvt1w= 0.00
+Dvt2w= 0.00 Nlx= 9.5000000E-08 W0= 0.00
+K3b= 0.00 Ngate= 5.0000000E+20
+Vsat= 1.0500000E+05 Ua= -1.2000000E-10 Ub= 1.0000000E-18
+Uc= -2.9999999E-11 Prwb= 0.00
+Prwg= 0.00 Wr= 1.0000000 U0= 8.0000000E-03
+A0= 2.1199999 Keta= 2.9999999E-02 A1= 0.00
+A2= 0.4000000 Ags= -0.1000000 B0= 0.00
+B1= 0.00
+Voff= -6.40000000E-02 NFactor= 1.4000000 Cit= 0.00
+Cdsc= 0.00 Cdscb= 0.00 Cdscd= 0.00
+Eta0= 8.5000000 Etab= 0.00 Dsub= 2.8000000
+Pclm= 2.0000000 Pdiblc1= 0.1200000 Pdiblc2= 8.0000000E-05
+Pdiblcb= 0.1450000 Drout= 5.0000000E-02 Pscbe1= 1.0000000E-20
+Pscbe2= 1.0000000E-20 Pvag= -6.0000000E-02 Delta= 1.0000000E-02
+Alpha0= 0.00 Beta0= 30.0000000
+kt1= -0.3700000 kt2= -4.0000000E-02 At= 5.5000000E+04
+Ute= -1.4800000 Ua1= 9.5829000E-10 Ub1= -3.3473000E-19
+Uc1= 0.00 Kt1l= 4.0000000E-09 Prt= 0.00
+Cj= 0.00138 Mj= 1.05 Pb= 1.24
+Cjsw= 1.44E-09 Mjsw= 0.43 Php= 0.841
+Cta= 0.00093 Ctp= 0 Pta= 0.00153
+Ptp= 0 JS=1.50E-08 JSW=2.50E-13
+N=1.0 Xti=3.0 Cgdo=2.786E-10
+Cgso=2.786E-10 Cgbo=0.0E+00 Capmod= 2
+NQSMOD= 0 Elm= 5 Xpart= 1
+Cgsl= 1.6E-10 Cgdl= 1.6E-10 Ckappa= 2.886
+Cf= 1.058e-10 Clc= 0.0000001 Cle= 0.6
+Dlc= 3E-08 Dwc= 0
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