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ERROR-Convergence problem in bias point calculation (PSpice)

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Cyrk

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convergence problem in bias point calculation

Hi.

I have yet another problem with Pspice

ERROR -- Convergence problem in bias point calculation

Last node voltages tried were:

NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE


( a0) 0.0000 ( a1) .7042 ( a2) 0.0000 ( a3) 0.0000

( a4) 0.0000 ( a5) 0.0000 ( cm) .3521 ( n1) .3521

( n2) .3506 ( n3) .1418 ( n4) .1418 ( n5) .1418

( n6) .1418 ( n7) .1418 ( n8) .1418 ( p1) .3521

( p2) .3506 ( p3) .1418 ( p4) .1418 ( p5) .1418

( p6) .1418 ( p7) .1418 ( p8) .1418 ( ia0) .7042

( ia1) 41.62E-06 ( ia2) .7042 ( ia3) .7042 ( ia4) .7042

( ia5) .7042 ( inn) .3521 ( inp) .3521 ( n4a) .1418

( n8a) .1418 ( p4a) .1418 ( p8a) .1418 ( vdd) .7042

( bias) .2603 ( X1.c) .1490 ( X4.c) .0294 (X1.a1) .1856

(X1.a2) .3394 (X1.b1) .1856 (X1.b2) .3394 (X4.a1) .2007

(X4.a2) .3238 (X4.b1) .2007 (X4.b2) .3238


These voltages failed to converge:

V(n4a) = 129.346 / 0.141803
V(n4) = 129.346 / 0.141803
V(p4a) = -129.038 / 0.141798
V(p4) = -129.038 / 0.141798
V(n8a) = -129.112 / 0.141791
V(n8) = -129.112 / 0.141791
V(p8a) = 129.42 / 0.141796
V(p8) = 129.42 / 0.141796
V(n5) = 129.418 / 0.141796
V(p5) = -129.11 / 0.141791
V(X1.c) = 0.146637 / 0.148958
V(X1.a1) = 0.183466 / 0.185578
V(X1.b1) = 0.165781 / 0.185578
V(X1.a2) = 0.341571 / 0.339387
V(p3) = -129.045 / 0.1418
V(X1.b2) = 0.359852 / 0.339387
V(n3) = 129.353 / 0.141805
V(n6) = 129.416 / 0.141796
V(p6) = -129.108 / 0.141791
V(X4.c) = 0.0388512 / 0.0294399
V(X4.a1) = -52.6554 / 0.200688
V(X4.b1) = 53.0535 / 0.20069
V(X4.a2) = 54.5665 / 0.323819
V(p7) = 129.456 / 0.141798
V(X4.b2) = -53.9154 / 0.323817
V(n7) = -129.147 / 0.141792

These supply currents failed to converge:

I(Vdd) = -1.41619e-010 / -1.18399e-010
I(Vid) = 1.68201e-008 / 8.77707e-012

These devices failed to converge:
X1.M7 X1.M9 X1.M11 X1.M8 X1.M10 X1.M12 X2.M0
X2.M1 X2.M2 X2.M3 XS1.Mm XS1.M0 XS1.M1 XS1.M2
XS1.M3 XS1.M4 XS1.M5 XS2.Mm XS2.M0 XS2.M1 XS2.M2
XS2.M3 XS2.M4 XS2.M5 XS3.Mm XS3.M2 XS3.M3 XS3.M4
XS3.M5 XS4.Mm XS4.M0 XS4.M1 XS4.M2 XS4.M3 XS4.M4
XS4.M5 X3.M0 X3.M1 X3.M2 X3.M3 X4.M1 X4.M2
X4.M3 X4.M4 X4.M5 X4.M7 X4.M9 X4.M11 X4.M6
X4.M8 X4.M10 X4.M12 X5.M0 X5.M1 X5.M2 X5.M3

ERROR -- Discontinuing simulation due to convergence problem

Any idea what can cause this and how to avoid it?
 

v_c

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these devices failed to converge

Looks like a problem with the MOSFETs -- which are modeled being modeled by the subcircuits (.subckt) definitions.

Try the following in your simulation
Code:
 .OPTIONS ITL1=400

This is the number of iterations the simulator will perform before giving up.
Let me know what happens.

Without seeing your schematic, my guess is that you have lots of transistors which might be modeled by expressions and they are somehow not producing a consistent set of results.

Best regards,
v_c

Added after 7 minutes:

You might also want to look at this document https://www.orcad.com/documents/community.an/pspice/PSpice_Convergence.pdf
starting on page 721 -- the section on "Bias Point (DC) Convergence"

Best regards,
v_c
 

yekmosafer

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these voltages failed to converge

I had this Problem too.
Tanks!
 

weak.element

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Re: ERROR-Convergence problem in bias point calculation (PSp

hi there

i have a problem in the simulation

anyone to help me


**** 04/08/10 18:27:24 ********* PSpice 9.2 (Mar 2000) ******** ID# 0 ********

** Profile: "SCHEMATIC1-sim" [ e:\inverter\orcad\abdulrahim-schematic1-sim.sim ]


**** CIRCUIT DESCRIPTION


******************************************************************************




** Creating circuit file "abdulrahim-schematic1-sim.sim.cir"
** WARNING: THIS AUTOMATICALLY GENERATED FILE MAY BE OVERWRITTEN BY SUBSEQUENT SIMULATIONS

*Libraries:
* Local Libraries :
* From [PSPICE NETLIST] section of d:\Program Files\Orcad\PSpice\PSpice.ini file:
.lib "nom.lib"

*Analysis directives:
.TRAN 0 5ms 0
.PROBE V(*) I(*) W(*) D(*) NOISE(*)
.INC ".\abdulrahim-SCHEMATIC1.net"



**** INCLUDING abdulrahim-SCHEMATIC1.net ****
* source ABDULRAHIM
C_C2 N00225 0 1n
X_U1 0 N00225 N00902 N00303 N00604 N00225 N00264 N00303 555C
V_V1 N00303 0 12Vdc
Q_Q1 N00303 N00902 0 Q2SC3258
C_C1 N00604 0 .1u
R_R2 N00264 N00303 10k
R_R1 N00264 N00225 133k

**** RESUMING abdulrahim-schematic1-sim.sim.cir ****
.END

**** 04/08/10 18:27:24 ********* PSpice 9.2 (Mar 2000) ******** ID# 0 ********

** Profile: "SCHEMATIC1-sim" [ e:\inverter\orcad\abdulrahim-schematic1-sim.sim ]


**** Diode MODEL PARAMETERS


******************************************************************************




X_U1.DIODE
IS 10.000000E-15
RS .01


**** 04/08/10 18:27:24 ********* PSpice 9.2 (Mar 2000) ******** ID# 0 ********

** Profile: "SCHEMATIC1-sim" [ e:\inverter\orcad\abdulrahim-schematic1-sim.sim ]


**** BJT MODEL PARAMETERS


******************************************************************************




Q2SC3258
NPN
IS 42.088000E-15
BF 182.44
NF 1
VAF 100
IKF 5.4542
ISE 329.880000E-15
NE 1.4548
BR 25.863
NR 1
VAR 100
IKR 1.1115
ISC 349.990000E-15
NC 1.2892
NK .33084
RC .073175
CJE 2.000000E-12
CJC 194.330000E-12
MJC .33333
TF 244.440000E-12
XTF 10
VTF 10
ITF 1
TR 101.110000E-09
XTB 1.5
CN 2.42
D .87


**** 04/08/10 18:27:24 ********* PSpice 9.2 (Mar 2000) ******** ID# 0 ********

** Profile: "SCHEMATIC1-sim" [ e:\inverter\orcad\abdulrahim-schematic1-sim.sim ]


**** Junction FET MODEL PARAMETERS


******************************************************************************




X_U1.JNEMOD
NJF
VTO -2.5
BETA 5.120000E-06


**** 04/08/10 18:27:24 ********* PSpice 9.2 (Mar 2000) ******** ID# 0 ********

** Profile: "SCHEMATIC1-sim" [ e:\inverter\orcad\abdulrahim-schematic1-sim.sim ]


**** MOSFET MODEL PARAMETERS


******************************************************************************




X_U1.PCHAN555 X_U1.NCHAN555
PMOS NMOS
LEVEL 1 1
L 100.000000E-06 100.000000E-06
W 100.000000E-06 100.000000E-06
VTO -.2 .2
KP 20.000000E-06 20.000000E-06
GAMMA 0 0
PHI .6 .6
LAMBDA 0 0
IS 10.000000E-15 10.000000E-15
JS 0 0
PB .8 .8
PBSW .8 .8
CJ 0 0
CJSW 0 0
CGSO 1.000000E-12 1.000000E-12
CGDO 1.000000E-12 1.000000E-12
CGBO 1.000000E-12 1.000000E-12
TOX 0 0
XJ 0 0
UCRIT 10.000000E+03 10.000000E+03
DIOMOD 1 1
VFB 0 0
LETA 0 0
WETA 0 0
U0 0 0
TEMP 0 0
VDD 0 0
XPART 0 0


X_U1.PCHAN555_OUT
PMOS
LEVEL 1
L 100.000000E-06
W 100.000000E-06
VTO -.2
KP 20.000000E-06
GAMMA 0
PHI .6
LAMBDA 0
IS 10.000000E-15
JS 0
PB .8
PBSW .8
CBD 200.000000E-12
CJ 0
CJSW 0
CGSO 1.000000E-12
CGDO 1.000000E-12
CGBO 1.000000E-12
TOX 0
XJ 0
UCRIT 10.000000E+03
DIOMOD 1
VFB 0
LETA 0
WETA 0
U0 0
TEMP 0
VDD 0
XPART 0


ERROR -- Convergence problem in transient bias point calculation


Last node voltages tried were:

NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE


(N00225) 3.9551 (N00264) 3.9551 (N00303) 3.9551 (N00604) 2.6367

(N00902)-15.25E+06 (X_U1.1) 157.6E-12 (X_U1.2) 1.3184 (X_U1.3)-8690.5000

(X_U1.4) .1660 (X_U1.5) -.6515 (X_U1.6) 4345.2000 (X_U1.7) .1660

(X_U1.8) .5358 (X_U1.9) 11.64E+06 (X_U1.10) 1.2990

(X_U1.11) 18.22E+06 (X_U1.12) 108.4E-12

(X_U1.13) 478.1E-12 (X_U1.14) 536.5E+06

(X_U1.15) .5504 (X_U1.16) 1.3036

(X_U1.17) 119.1E-12 (X_U1.18) 1.8083

(X_U1.19) 48.42E-12 (X_U1.20) 238.8E-06

(X_U1.21) .7995 (X_U1.22) 154.2E-06

(X_U1.23) -.3878 (X_U1.24) 1.3036

(X_U1.25) 34.98E-12 (X_U1.VDD) 1.3036


These voltages failed to converge:

V(N00902) = 2.127nV \ -15.25MV
V(X_U1.9) = -70.92V \ 11.64MV
V(X_U1.10) = 1.205nV \ 1.299V
V(X_U1.11) = -6.721V \ 18.22MV
V(X_U1.18) = 1.734V \ 1.808V
V(X_U1.14) = 1.668V \ 536.47MV
V(X_U1.15) = 375.19mV \ 550.39mV

These supply currents failed to converge:

I(X_U1.E_EMIR) = -924.39nA \ 932.22KA
I(V_V1) = 4.852A \ 157.72MA

These devices failed to converge:
X_U1.M_U2_U1_M4 X_U1.M_U2_U1_M3 X_U1.M_U2_U1_M6 X_U1.M_U2_U1_M8
X_U1.M_U2_U1_M1 X_U1.M_U2_U1_M2 X_U1.M_U2_U1_M5 X_U1.M_U2_U1_M7
X_U1.M_U2_U2_M8 X_U1.M_U2_U2_M2 X_U1.M_U2_U2_M5 X_U1.M_U2_U4_M1
X_U1.M_U2_U4_M2 Q_Q1

ERROR -- Discontinuing simulation due to convergence problem
 

keith1200rs

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Convergence problems like that are usually caused by floating nodes i.e. not driven by an source. Check you circuit for floating gates and missing gate-drain connections in current mirrors.

The reported non-converging nodes can give a clue, but can be unhelpful if there are too many. Posting your schematic may help.

Keith
 

LvW

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Re: ERROR-Convergence problem in bias point calculation (PSp

Yes, as KEITH said, the error report does not help at all (Do you expect, that someone reads this long report?).
Sending the schematic is the best way to give some help.
 

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