How to do noise analysis in Cadence?(50 points)

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Karthikeya

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transient noise cadence

hi everyone,
i want to know how to simulate noise in Cadence Analog Env. How to use 'ports' for simulating input noise?
Also, does the transient analysis give an estimate of noise in the output? For example, in ADC, if I find the rms value of difference of transient signal input and reconstructed output ...will it give me the quantisation noise + other noise?

regards
 

cadence transient noise

Hi,
Section 2-23 of the PSpice A/D Schematics Version User's Guide describes very nicely witha n example how to do the noise analysis.
You can access the manuals clicking on help-> manuals in the Top menu of the Capture-CIS.
 

spectre transient noise analysis

Hello Karthikeya:

Supposing you know how to do AC analysis,
Choose noise analysis with the band of interest (e.g. 20~20e3)
select voltage source for compatibility with HSPICE result.
AC analysis has to remain enabled.
When completed, select Results-->Print-->Noise Summary.
Good Luck!
 

cadence transient noise analysis

Dear Karthikeya,

There are two things to note here. All the noise analysis the other people are referring to are ac noise simulations. But, if you have to simulate the quantization noise and the noise floor of the ADC,you have to take the output and subject it to FFT( or DFT in case of calculator in the Cadence environment). The FFT/DFT would give you the peaks of the RMS values of the signal and the the spur peaks for the quantization noise levels.

Hence you can calculate the Noise Floor, SFDR, SNDR,etc.
 

    K

    Karthikeya

    Points: 2
    Helpful Answer Positive Rating
transient noise analysis spectre

hi Vamsi Mocherla,
Thank you for sharing your thoughts...but still i havent got all the answers i wanted. I use 'spectre' simulator in Cadence...and actually my question was how to do noise analysis using spectre i.e. pss analysis and also including input noise 'ports'.
Lastly, can i trust the results of the example i mentioned earlier for finding the noise using transient analysis.
Since your's was a partial answer...i can only give you partial points.

regards
 

transient noise in cadence

Dear kartikeya,

For pss analysis, you need Spectre RF license. Coming to using the input ports, the ports are defined by the nets/pins where the analysis should start. Actually noise analysis assumes a two port network and then does the analysis. Hence it asks for input and output ports.

Ofcourse, you can trust the transient analysis. The transient analysis is a realworld condition. All the components including noise are inbuilt into the results.
 
spectre noise analysis

Well actually you can use the pss in Spectre not SPectre RF. I believe it was made accessible from version5x higher.

I do not have it right in front of me and it is some time I run it but in general you select the pss and set the port on the input resp output. run the sim and in calculator you select s11 swhatever parameters and just plot those.

In case you would be wondering about models - for the params like s11 etc you can use just basic mos models but those are not exactly extracted at high frequencies (unless you have tru rf models) so you would be a bit off.
For noise sims you need to have correct noise models or your results won't be even close and you would get "default" "built-in" noise results.
 

    K

    Karthikeya

    Points: 2
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spectre version transient noise analysis

i have finally learned to do noise noise analysis in cadence...thanks to all your replies. I have already distributed all the points based on the closeness of the answer...

thank you everybody
regards
 

cadence schematic tutorial noise analysis

PSS+pnoise approach is commonly used, especially for case like VCO design. However, sometimes it take days to find the correct convergence condition, and the result is meanful only if you cross-check it with actual test result.
 

cadence+noise transient

please just check the cadence spectre RF manual, in which there are very detailed description and examples. from there you can find much better explaination and step-by-step proceduures than all the answers here.
 

spectre ade noise analysis

u open (dc , ac,noise analysis) and put the noise parameter inside the each component [/b][/u]
 

donoise+spectre

Hi,

As our company use new version of Cadence 5141 USR3, int he spectre ADE environment, spectre's transient analysis has option "transient noise" analysis.
interesting asking Cadence engineering, yes, new function.
 

what is transient noise cadence

Can anyone tell me how to make noise analyisis in either OrCAD or Advanced Desing System (ADS) ??

I will be thankful for any help...

Regards,
Ahmad,
 

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