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#1 Nov 18, 2020
Viawind
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Error in Voltage Probe

I am new to PSpice for TI. I am trying to replicate a simulation of a charge sensitive amplifier using the THS 4503 fully Differentiall OpAmp that previously worked in TINA-TI. I have a voltage probe 'V' on the output. When run I get the error in the "SCHEMATIC1-bias" file

ERROR(ORPSIM-16103): Invalid value
.OPTIONS THREADS= 2
.PROBE64 V(alias(*)) I(alias(*)) W(alias(*)) D(alias(*)) NOISE(alias(*))
.INC "..\SCHEMATIC1.net"

I have not been able to find the invalid value error that I assume is associated with the probe (?)

Thanks for any sggestions.

 

Sun, 2021-05-16 06:58
alok
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Typically error message is printed next to line causing error. Share few more lines from your output file to understand the cause of error 

Tue, 2021-05-18 13:11
Viawind
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Thanks alok for picking up on this old post. I have more or less given up on trying to get my charge sensitive amplifier model working in PSpice. I think I did eventually solve the voltage probe error but continued to run into errors that seemed to make little sense. I could copy the model files to you if you'd be willing to look them over and I'd be most grateful for any assistance. I did query TI about this particulat balanced opamp device model and they assure me it is correct. I am sure I am being dumb somewhere.

Tue, 2021-05-18 23:46
alok
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Please do share the same and will have a look. Happy to help. 

Mon, 2021-05-24 17:54
Viawind
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Thanks for the offer to help. Here is the current output file text.

**** 05/24/21 15:17:43 ******* PSpice 17.4.0 (Nov 2018) ******* ID# 0 ********

** Profile: "SCHEMATIC1-bias" [ c:\users\richard\documents\pspice\ic preamp-pspicefiles\schematic1\bias.sim ]

**** CIRCUIT DESCRIPTION

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

** Creating circuit file "bias.cir"
** WARNING: THIS AUTOMATICALLY GENERATED FILE MAY BE OVERWRITTEN BY SUBSEQUENT SIMULATIONS

*Libraries:
* Profile Libraries :
* Local Libraries :
* From [PSPICE NETLIST] section of C:\SPB_Data\cdssetup\OrCAD_PSpiceTIPSpice_Install\17.4.0\PSpice.ini file:
.lib "nom_pspti.lib"
.lib "nom.lib"

*Analysis directives:
.AC DEC 5 1M 100M
.NOISE VAC VSource 5
-------$
ERROR(ORPSIM-16291): Must be independent source (I or V)
.SAVEBIAS "TestBias" OP
.OPTIONS FILEMODELSEARCH
.PROBE64 V(alias(*)) I(alias(*)) W(alias(*)) D(alias(*)) NOISE(alias(*))
.INC "..\SCHEMATIC1.net"

**** INCLUDING SCHEMATIC1.net ****
* source IC PREAMP
X_U1 N15046 N15037 N15140 0 N18008 N17988 N19112 THS4503
X_TX1 N16004 N16008 N15191 0 SCHEMATIC1_TX1
R_R4 N15037 N17988 100k TC=0,0
R_R5 N15046 N18008 100k TC=0,0
C_C1 N15037 N17988 5p TC=0,0
C_C2 N15046 N18008 5p TC=0,0
C_C3 N20962 N15037 22p TC=0,0
C_C4 N16858 N15046 22p TC=0,0
R_R6 0 N15191 100 TC=0,0
V_V1 N15140 0 12V
C_C5 0 N19112 1uF TC=0,0
C_C6 N17988 N16004 100n TC=0,0
C_C7 N18008 N16008 100n TC=0,0
R_R8 0 N16858 1M TC=0,0
R_R9 0 N16008 1M TC=0,0
R_R10 N19112 0 1M TC=0,0
V_V2 N20499 0 DC 0Vdc AC 1Vac 0
X_TX3 N20499 0 N20962 N16858 SCHEMATIC1_TX3

.subckt SCHEMATIC1_TX1 1 2 3 4
K_TX1 L1_TX1 L2_TX1 1
L1_TX1 1 2 10mH
L2_TX1 3 4 2.5mH
.ends SCHEMATIC1_TX1

.subckt SCHEMATIC1_TX3 1 2 3 4
K_TX3 L1_TX3 L2_TX3 1
L1_TX3 1 2 10uH
L2_TX3 3 4 10uH
.ends SCHEMATIC1_TX3

**** RESUMING bias.cir ****
.END

That looks like a naming conflict to me but renaming does not help. I am not sure if the schematic netlist is sufficient for you to reconstruct the project. What other files would you need ?

Thanks, Dick (Viawind)

Tue, 2021-05-25 03:11
dshikhar
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Looking at the output file, the issue seems to be with noise analysis settings in your simulation profile. 

Please make sure in noise analysis the "Output Voltage" is defined as V(net_name). 

For example if you want to calculate the noise at a net name OUT, then output voltage in noise analysis should be V(OUT)

Hope this helps.

 

Mon, 2021-05-31 12:27
Viawind
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Hi Dshikhar,

Thanks, that does seem to be part of the problem. I changed the Output Voltage to be V(Nxxxx) wgere Nxxxx was the Net Name reported by pointing at the wire connection. Running the simulation resulted in a request to add resistance between my programable voltage source and the input transformer that has zero dc resistance. I did that in spite of already having the voltage source set to 0V dc and reran the simulation. Then unfortunately PSpice crahed and destroyed the model. I'll have to reconstruct it. Where should I find the Net Name for the output of my model ? Sorry to be so dumb.

Mon, 2021-05-31 16:26
Viawind
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Ok I found out how to assign Names to the points in the net. Now I am trying to find the source of ab "illegal integer" error.

Mon, 2021-05-31 17:57
Viawind
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Ok, I got the AC Analysis to run without error but with no sensible output. Back to the manual to see what I am doing wrong. Thanks for the help.

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