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  3. Is there a ready-to use oscillator model with PHN in Cadence...

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Is there a ready-to use oscillator model with PHN in Cadence available

HoWei
HoWei over 4 years ago

I am simulating a PLL and need a reference oscillator model with phase-noise.

I want to perform transient and PSS simulations to observe the output phase-noise.

Before starting to model the OSC in Verilog-A, I searched in the analogLib, basic, pllLib, etc. but did not find such a model.

I am pretty sure that such a model is available somewhere in Cadence.

Can you please point me to such an oscillator model ?

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  • HoWei
    HoWei over 4 years ago

    The "spectre -help vsource"  says:


    Noise Parameters:
    80 noisefile Name of the file containing excess spot noise data in the form of frequency-noise pairs. The noise can be specified as the spectral density in V^2/Hz, or as single-sideband phase noise in dBc. The parameter noisetype
    determines how Spectre interprets the noise data. Noise data file contains an optional parameter noisetype. Noisetype parameter in data file has identical definition to same parameter noisetype and supersedes it. It
    is intended to prevent misuse of the datafile.
    81 noisevec=[...] V^2/Hz
    Excess spot noise as a function of frequency in the form of frequency-noise pairs. The parameter noisetype determines how Spectre interprets the noise data.
    82 noisetype=noisevoltage
    Noisetype parameter specifies the units and source of noise data. When this parameter is set to noisevoltage, the noise data represents the noise spectral density in V^2/Hz of noise measured at the output of a driven
    circuit. When set to ssbphasenoise, the noise data represents the single-sideband phase noise in dBc measured at the output of a free oscillator. For noisetype=noisevoltage, the frequencies are taken as absolute. For
    ssbphasenoise, the frequencies are offset from the carrier. Noisetype=ssbphasenoise can be used only with pnoise, qpnoise, hbnoise analyses, the noise source will be ignored in transient noise and AC noise analyses.
    Possible values are noisevoltage and ssbphasenoise.
    83 noiseinterp=linear
    Determines how the specified noise data is interpolated. This parameter only applies to noisetype=noisevoltage. When set to linear, interpolation is linear over both axes. When set to loglog, Spectre uses log
    interpolation over both axes. Possible values are linear and loglog.
    84 isnoisy=yes Determines whether vsource should generate noise. Possible values are no and yes.

    How to use this ?

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  • HoWei
    HoWei over 4 years ago

    The "spectre -help vsource"  says:


    Noise Parameters:
    80 noisefile Name of the file containing excess spot noise data in the form of frequency-noise pairs. The noise can be specified as the spectral density in V^2/Hz, or as single-sideband phase noise in dBc. The parameter noisetype
    determines how Spectre interprets the noise data. Noise data file contains an optional parameter noisetype. Noisetype parameter in data file has identical definition to same parameter noisetype and supersedes it. It
    is intended to prevent misuse of the datafile.
    81 noisevec=[...] V^2/Hz
    Excess spot noise as a function of frequency in the form of frequency-noise pairs. The parameter noisetype determines how Spectre interprets the noise data.
    82 noisetype=noisevoltage
    Noisetype parameter specifies the units and source of noise data. When this parameter is set to noisevoltage, the noise data represents the noise spectral density in V^2/Hz of noise measured at the output of a driven
    circuit. When set to ssbphasenoise, the noise data represents the single-sideband phase noise in dBc measured at the output of a free oscillator. For noisetype=noisevoltage, the frequencies are taken as absolute. For
    ssbphasenoise, the frequencies are offset from the carrier. Noisetype=ssbphasenoise can be used only with pnoise, qpnoise, hbnoise analyses, the noise source will be ignored in transient noise and AC noise analyses.
    Possible values are noisevoltage and ssbphasenoise.
    83 noiseinterp=linear
    Determines how the specified noise data is interpolated. This parameter only applies to noisetype=noisevoltage. When set to linear, interpolation is linear over both axes. When set to loglog, Spectre uses log
    interpolation over both axes. Possible values are linear and loglog.
    84 isnoisy=yes Determines whether vsource should generate noise. Possible values are no and yes.

    How to use this ?

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  • HoWei
    HoWei over 4 years ago in reply to HoWei

    Okay, that will do it :

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  • ShawnLogan
    ShawnLogan over 4 years ago in reply to HoWei

    Dear HoWei,

    Ken Kendurt has a popular verilogA model that he has published. The model for a VCO that includes accumulating jittter is I Section 7.3 and explicitly in "Listing 4" at URL:

    designers-guide.org/.../PLLjitter.pdf

    I hope this provides some insight and help!

    Shawn

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