PSpice Non-Inverting Opamp Simulation Convergence Error

Hello,

I'm trying to model a very basic non-inverting amplifier using a Burr-Brown OPA134 opamp using OrCAD PSpice A/D 10.0 Demo, freely available from OrCAD's website.

I have zipped my design and put it up on:

formatting link

The model uses an OPA134, created by following the instructions at:

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and using the SPICE model provided by TI for the OPA134.

The model also uses a 1k and a 10k resistor for the feedback network and a VAC source (Vac = 1, Vdc = 0) as input to the non-inverting input of the opamp.

I have played around with the simulation of this circuit for a while now, but I keep getting the following (entire PSpice output file follows):

What could the problem be?

Chris

**** 09/16/04 13:13:25 ************** PSpice Lite (Jan 2003) ***************** ** Profile: "SCHEMATIC1-preamp" [ C:\\ORCAD\\work\\preamp\\preamp-PSpiceFiles\\SCHEMATIC1\\preamp.sim ]

**** CIRCUIT DESCRIPTION

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

** Creating circuit file "preamp.cir"

** WARNING: THIS AUTOMATICALLY GENERATED FILE MAY BE OVERWRITTEN BY SUBSEQUENT SIMULATIONS

*Libraries:

  • Profile Libraries : ..INC "C:\ORCAD\work\preamp\preamp-PSpiceFiles\SCHEMATIC1\preamp\preamp_profile.inc"
  • Local Libraries :

**** INCLUDING preamp_profile.inc **** ..STMLIB ".\\preamp.stl"

**** RESUMING preamp.cir **** ..LIB "C:/orcad/orcad_10.0_demo/tools/pspice/library/eval.lib" ..LIB "C:/orcad/orcad_10.0_demo/tools/pspice/UserLib/opa134.lib"
  • From [PSPICE NETLIST] section of C:\orcad\orcad_10.0_demo\tools\PSpice\PSpice.ini file: ..lib "nom.lib"

*Analysis directives: ..AC DEC 100 100 1000000 ..OPTIONS STEPGMIN ..PROBE V(alias(*)) I(alias(*)) W(alias(*)) D(alias(*)) NOISE(alias(*)) ..INC "..\\SCHEMATIC1.net"

**** INCLUDING SCHEMATIC1.net ****
  • source PREAMP V_V1 N08548 GND_POWER DC 0Vdc AC 1Vac V_V2 GND_POWER N092391 20Vdc R_R1 GND_POWER N08368 1k V_V3 N092720 GND_POWER 20Vdc R_R2 N08368 N08386 10k X_U1 N08548 N08368 N092720 N092391 N08386 OPA134

**** RESUMING preamp.cir **** ..END

**** 09/16/04 13:13:25 ************** PSpice Lite (Jan 2003) ***************** ** Profile: "SCHEMATIC1-preamp" [ C:\\ORCAD\\work\\preamp\\preamp-PSpiceFiles\\SCHEMATIC1\\preamp.sim ]

**** Diode MODEL PARAMETERS

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

X_U1.DX IS 800.000000E-18

**** 09/16/04 13:13:25 ************** PSpice Lite (Jan 2003) ***************** ** Profile: "SCHEMATIC1-preamp" [ C:\\ORCAD\\work\\preamp\\preamp-PSpiceFiles\\SCHEMATIC1\\preamp.sim ]

**** Junction FET MODEL PARAMETERS

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

X_U1.JX PJF VTO -1 BETA 1.010000E-03 IS 2.500000E-15

ERROR -- Convergence problem in bias point calculation

Last node voltages tried were:

NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE

(N08368)-10.00E+09 (N08386)-10.00E+09 (N08548)-10.00E+09 (X_U1.6) ..0044

(X_U1.7)-10.00E+09 (X_U1.8)-10.00E+09 (X_U1.9) 0.0000 (N092391)-10.00E+09

(N092720)-10.00E+09 (X_U1.10)-10.00E+09

(X_U1.11)-10.00E+09 (X_U1.12)-10.00E+09

(X_U1.53)-10.00E+09 (X_U1.54)-10.00E+09

(X_U1.90) -.0461 (X_U1.91) 40.0000

(X_U1.92) -40.0000 (X_U1.99)-10.00E+09

(GND_POWER)-10.00E+09

These voltages failed to converge:

V(N08548) = -10.00GV \\ -10.00GV V(GND_POWER) = -10.00GV \\ -10.00GV V(N092391) = -10.00GV \\ -10.00GV V(N08368) = -10.00GV \\ -10.00GV V(N092720) = -10.00GV \\ -10.00GV V(N08386) = -10.00GV \\ -10.00GV V(X_U1.11) = -10.00GV \\ -10.00GV V(X_U1.12) = -10.00GV \\ -10.00GV V(X_U1.7) = -10.00GV \\ -10.00GV V(X_U1.10) = -10.00GV \\ -10.00GV V(X_U1.99) = -10.00GV \\ -10.00GV V(X_U1.53) = -10.00GV \\ -10.00GV V(X_U1.54) = -10.00GV \\ -10.00GV V(X_U1.8) = -10.00GV \\ -10.00GV

**** Interrupt ****
Reply to
Apparatus
Loading thread data ...

You have no node 0 (zero)

Add a ground symbol

"C:\\ORCAD\\work\\preamp\\preamp-PSpiceFiles\\SCHEMATIC1\\preamp\\preamp_profile.inc"

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
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Reply to
Jim Thompson

You need a 0 (ground) symbol out of the source library. That is the only ground that works for simulation in Capture. Or, just rename the ground symbol you used to 0.

Apparatus wrote:

"C:\\ORCAD\\work\\preamp\\preamp-PSpiceFiles\\SCHEMATIC1\\preamp\\preamp_profile.inc"

--
Charlie
--
Edmondson Engineering
Unique Solutions to Unusual Problems
Reply to
Charles Edmondson

Thank you both, this solved the problem.

Cheers, Chris

Reply to
Apparatus

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