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  3. Problems running transient noise simulation

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Problems running transient noise simulation

Wes8
Wes8 over 12 years ago

Hi,

I'm running IC6.1.4.5 and trying to run a transient noise simulation on an amplifier but can't seem to get the noise generation to work. I've simplified the test bench to an ideal current source feeding into a 1kohm resistor to verify basic functionality. No noise was generated. I've done all the basics - turned noise generation ON within the resistor settings, followed the user manual instructions on setting up the transient noise test parameters (fmin, fmax, noise contribution ON, update at fmax, selected the resistor). I've verified that this test bench does work with AC noise analysis. Am I missing something here?

Thanks in advanced for your help.

 

Wes 

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  • Andrew Beckett
    Andrew Beckett over 12 years ago

    Wes,

    No idea what you're doing that is causing this not to work. I did the same thing, and in the netlist, I get:

     // Generated for: spectre
    // Generated on: Jun 10 17:34:46 2013
    // Design library name: mylib
    // Design cell name: trannoise
    // Design view name: schematic
    simulator lang=spectre
    global 0

    // Library name: mylib
    // Cell name: trannoise
    // View name: schematic
    R0 (op 0) resistor r=1K
    I0 (op 0) isource dc=100u type=dc
    simulatorOptions options reltol=1e-3 vabstol=1e-6 iabstol=1e-12 temp=27 \
        tnom=27 scalem=1.0 scale=1.0 gmin=1e-12 rforce=1 maxnotes=5 maxwarns=5 \
        digits=5 cols=80 pivrel=1e-3 sensfile="../psf/sens.output" \
        checklimitdest=psf
    tran tran stop=1m noisefmax=1G noisefmin=1k noiseseed=1 noiseupdate=fmax \
        noiseon=[ R0] write="spectre.ic" writefinal="spectre.fc" \
        annotate=status maxiters=5
    finalTimeOP info what=oppoint where=rawfile
    modelParameter info what=models where=rawfile
    element info what=inst where=rawfile
    outputParameter info what=output where=rawfile
    designParamVals info what=parameters where=rawfile
    primitives info what=primitives where=rawfile
    subckts info what=subckts  where=rawfile
    saveOptions options save=allpub

    Note I don't really need to set noiseupdate or the noiseon parameter; it just works OK without this.

    If I plot the voltage at node op, I get the attached graph.

    Andrew.

     

    • trannoise.png
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