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Why OCEAN script produce different analysis result from ADE?

datao

Hi,

I uses a scripts to analyze phase noise of a VCO at different control voltage. I found some data points are significantly different from ADE produced. Then I saved script in ADE and load the script in ocean. The phase noise calculated with ocean script is -80. But at ADE, it is -100. Anyone can tell me how to solve this problem? Thanks! The save script is attached as below. The frequency calculated are consisten, but phase noise are different from ocean script.

 

 ocnWaveformTool( 'wavescan )
fp=outfile(sprintf(nil "%s/tmp.csv" resultPATH) "a")
fprintf(fp "vc ts cf wc freq amp vcom phasenoise\n")

simulator( 'spectre )
design(     "/users/dtgong/simulation/testLCVCO/spectre/schematic/netlist/netlist")
resultsDir( "/users/dtgong/simulation/testLCVCO/spectre/schematic" )
modelFile(
    '("/home/dtgong/peregrine/PSC_Release_3.8.1/Rel_3.8.1/gc/models/psa/spectre/modellib.scs" "Nominal")
)
analysis('tran ?stop "200n"  ?errpreset "conservative"  )
analysis('pnoise ?sweeptype "relative"  ?relharmnum "1"  ?start "10K"  
        ?stop "100M"  ?maxsideband "7"  ?p "/vp0"  ?n "/vn0"  
        ?oprobe ""  ?iprobe ""  ?refsideband ""  ?ppv ""  )
analysis('pss ?fund "5.0G"  ?harms "7"  ?errpreset "conservative"  
        ?tstab "500n"  ?p "/vp0"  ?n "/vn0"  ?ppv ""  )
desVar(      "wc" 30u    )
desVar(      "wb" 10u    )
desVar(      "cf" 220p    )
desVar(      "r" 10    )
desVar(      "global_use_preLPE" 1    )
desVar(      "vc" 1.1    )
desVar(      "cl" 60f    )
envOption(
    'autoDisplay  nil
)
save( 'i "/I0/I0/R0/MINUS" "/I0/I0/L0/PLUS" "/I0/I0/L1/PLUS" )
converge( 'ic "/vn0" "0.01" )
temp( 27 )
run()
selectResult( 'tran )
;plot(getData("/vp0") getData("/vn0") getData("/I0/vb") getData("/I0/I0/R0/MINUS") getData("/I0/I0/L0/PLUS") getData("/I0/I0/L1/PLUS") getData("/I0/I0/vtail") )
freq = frequency(clip((VT("/vp0") - VT("/vn0")) 1e-08 4e-08))
;plot( freq ?expr '( "freq" ) )
Phase\ Noise\;\ dBc\/Hz\,\ Relative\ Harmonic\ \=\ 1 = phaseNoise(1 "pss_fd" ?result "pnoise")
;plot( Phase\ Noise\;\ dBc\/Hz\,\ Relative\ Harmonic\ \=\ 1 ?expr '( "Phase Noise; dBc/Hz, Relative Harmonic = 1" ) )
ph_1M = value(phaseNoise(1 "pss_fd" ?result "pnoise") 1000000.0)
;plot( ph_1M ?expr '( "ph_1M" ) )
;freq0 = (freq (VT("/vp0") - VT("/vn0")) "rising" ?xName "time" ?mode "auto" ?threshold 0.0 ?histoDisplay nil ?noOfHistoBins nil)
;plot( freq0 ?expr '( "freq0" ) )
fprintf(fp "%.3fGHz %f\n"  freq*1e-9 ph_1M)
close(fp)

 

Thanks a lot,

 

Datao

 

Parents

  • Datao,

    Given that in both cases a netlist for spectre is assembled and simulated, I would take the "input.scs" in the netlist directory as simulated in ADE - copy it elsewhere - and then do the same for the OCEAN script - and do a "diff" between the two to see what differences there are. There is bound to be some difference (otherwise the results would be the same) - maybe that will pinpoint the reason and it will become clear if there's something missing (or different) in the OCEAN script.

    Regards,

    Andrew.

Reply

  • Datao,

    Given that in both cases a netlist for spectre is assembled and simulated, I would take the "input.scs" in the netlist directory as simulated in ADE - copy it elsewhere - and then do the same for the OCEAN script - and do a "diff" between the two to see what differences there are. There is bound to be some difference (otherwise the results would be the same) - maybe that will pinpoint the reason and it will become clear if there's something missing (or different) in the OCEAN script.

    Regards,

    Andrew.

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