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## [Moved]: Divider pnoise in the PLL

Hi, i want to get the overall pnoise of the PLL in Matlab, so i firstly stimulus the pnoise of several components in the cadence ADE, the simulation pnoise of Divider is about -120~-130dBc/Hz, and the noise power spectral density is about -160~-170dB/sqrt(Hz), i want to know is it normal? if (...)

Hi everyone, I am designing an offset cancellation circuit and I want to do a noise simulation. My goal is to do the simulation using the circuit without the offset cancellation technique and then using the same topology using the offset cancellation technique and compare both noises. I have tried the (...)

## CS Differential LNA simulation problem !

generally the noise figure of differential LNA is lower than single ended.Wrong. NF of differential amplifier is always larger since noises are uncorrelated. Do u think baluns add noise to circuit?If you use "analogLib/ideal_balun" in cadence dfII, it is noiseless.

## S Parameter in spectre and ADS

See You can see a defintion of NF(k) in Keysight ADSsim and GoldenGate. If you use more than three ports, e.g, port1=RF, port2=IF, port3=LO, NF(2) is different from NF of cadence Spectre. Here you have to use resistor + vsin instead of port3=LO.

## how to simulate the input refered noise of an integrator in cadence/spectre

As the figure shows, do the noise simulation, but the output and negative input node of the amplifier is not "directly" biased, how to get the input referred noise data from simulation? Thanks 129361

Hello, As you know, PVT simulation is process, voltage and temperature. About process simulation, you can use monte carlo simulation ( samples > 10). To voltage simulation, you will change voltage supply. For example, voltage supply is 3.3 V, you can run 3.2-3.4V and may be plus Vsin (noise). To (...)

## Opamp input current noise simulation in cadence

I suppose you want to simulate this in a true application, meaning the inputs are controlled by a generator with known output impedance? In this case connect the inputs with noiseless resistors to the required bias voltage. Or subtract the resistors noise, if you can't find noiseless resistors in your libs.

## [Moved]: Problems in simulation noise of amplifier

Probably the bandwidth of your opamp is smaller than flicker noise corner frequency?

## XO simulation: HB convergence issue

Hi all, I'm currently work on an oscillator using XO. I want to characterize the phase noise and I've some strange behavior. I've set the simulator by following the link below. Using HB and HB noise, f

## thermal noise simulation in cadence virtuoso IC 616

Hi I have found the following thread, which i am trying to understand currently. In that they tried to measure the thermal noise of a resistor. I have a doubt in that, Do we need to connect any source to this transistor or we just use the resistor without any sources before calculating noise..

The noise figure obtained by simulation with ADE L increases after and upgrade from release 6.1.5 to 6.1.6.080 of cadence Virtuoso. The design kit is the same for both releases. Any one who had a similar problem and who may know its origin ? Regards, Aba

## Relaxation Oscillator Jitter Simulation in cadence - Eye diagram confusion...

Dear All, I am designing a conventional relaxation oscillator. The moninal frequency is around 2.85 MHz. When I try to run the transient noise simulation and use calculator to obtain the eye diagram, I got some weird diagram and i am very much confused. Attached you can see some waveforms obtained using the function eye diagram. The se

## cadence noise simulation results are different by two result display methods

gangs, I am running .noise analysis in cadence's spectre. Two methods display the simulation results: method 1. plot equivalent input noise. This can be done by: locate spectre simulator menu-->results-->direct plot-->equivalent input noise. A figure will pop out. Then go to calculator's RMS function. The (...)

## Noise correlation simulation in pnoise

Hi, 1. I am using IC6.1.6-64b.500.1 and my simulator version is 10.1.1.296.isr18 64 bit 2. I am simulating a basic downconversion mixer as shown in attached figure. I want to know the correlation between noise at RF (red) and noise at IF (blue). I tried to follow the following article:

## Minimum Detectable Photocurrent- Image sensor- Post Layout simulation- cadence

This is a many-layered question and one which simulation can only approximate. Minimum detectable, vs minimum -reliably- detectable, just by itself, has dark current, telegraph noise, detector circuitry threshold / noise contribution aspects. Not that almost all of these push into areas that often are poorly modeled or not well modelable (...)

## designing a delay circuit using cmos logic

hello ...i tried many circuts like cascading of inverters Hi, for simulating your ring oscillator, I think in cadence ADE, you need to set simulation-> Convergence Aids-> Initial condition-> click on say the o/p node of the oscillator->apply '0 V' in the dialog. This will help in adding the initial noise for oscil

## Cadence 6, distribute tran noise job on multiple cpu

Dear all, anyones whos knows how to distribute a tran noise simulation jobs on different cpus? How to distribute the intial seed? thx.

## how to calculate noise factor in cadence?

I am using spectre to measure the noise performance of my schematic with spectre in cadence . I wonder how the software to calculate the noise factor with the input noise and output noise . The simulation results show that noise factor doesn't equal to output (...)

It is simply due to limitation of small signal noise analysis in frequency domain. We can never get reliable result of phase noise for small offset frequency. This is true for any vendor's simulator such as Agilent ADSsim, Agilent GoldenGate, cadence Spectre, Synopsys HSPICE, Mentor Eldo, etc. See the followings. www.designers-guide.o

## kT/C noise simulation

Hi everyone, I'm just wondering if there is a way to simulate the kT/C noise and/or the 1/f noise? I'm using cadence Virtuoso with eldoD simulator or questa. If there is no way, should I satisfy with some basic hand written equations?? Thank you

Hi all I would like to add noise source for my simulation under cadence but have no idea how to do so. Anyone has any idea how to do that?

In the standard noise simulation, ideal resistor noise (calculated from its resistance value) is included (there may be an option to select/deselect it). Same is true for all the devices, if their models include the corresponding parameters.

## Noise Figure in mixer - simulation by using Cadence

Why in simulation by using cadence, even a simple basic mixer also showing very high value. There is any setting or consideration? bcos in most of Journals they can achieve NF below 15dB, i have been tried many ways but NF can not achieve below 18dB. Please anyone help me. Thanks advance.

## why the phase noise is greater than 0 dBc/Hz

Hi I am using cadence pnoise for VCO (ring) simulation. Why my pnoise is greather than 0 dBc as the offset is close to 0? It is also 60 dBc at 1 Hz. Is it correct??

## What value of port impedance should be in Noise simulation with Cadence Spectre?

Hi guys, I've gotten something unsure about noise factor. Hope for help here. The noise Factor is defined as below. N = (Na+G*Ns)/(G*Ns). Different Ns produces different N. And in cadence spectre, the noise source is usually a port. The impedance of the port provides the thermal noise 4kTRB V^2, (...)

## Dynamic Link for phase noise simulation problem

Dear All, I'm using ADS Dynamic Link to simulate an LC oscillator schematic from cadence(using ibm130nm PDK). With the ADS HB simulation, all the simulation results such as oscillation freq are obtained correctly except for the phase noise(pnmx). When I list the pnmx in the result browser window, the value shows "NaN". (...)

## Is dcmatch analysis in Cadence useful?

With Monte Carlo you might have to run 30-100 simulations before you got a good estimate of the standard deviation (SD) due to random mismatch. On the other hand, DC match is a sensitivity analysis that is much like a noise analysis. It will give you the SD in a single simulation, making it very useful for large circuits. The downside is (...)

## PSS and Pnoise Simulation setup for frequency dividers in Cadence

Hi, I am trying to simulate the phase noise of a bunch of frequency dividers. My oscillator runs at 12-17 GHz. I use frequency dividers to generate quadrature signals and cover the desired frequency bands. Currently I am using a divide-by-2 conventional CML divider followed by two divide-by-2 and divide-by-3 frequency dividers to cover two bands

## phase noise analysis of ring oscillator with cadence rf

Hey I´d like to do a phase noise analysis with cadence virtuoso. In my pss analysis the estimated frequency (direct plot harmonic frequency) does not match to the beat frequendy i´ve entered in the simulation set up file. to set up the simulation i followed the spectre rf workshop. what could be the problem there? (...)

## how to measure parameters of a operational transconductance amplifier(OTA) design

1）~3） AC simulation or STB analysis 4) DC sweep 5) transient 6) DC sweep 7) noise analysis

## How to simulation PLL loop filter noise by cadence spectre

Dear all, How to simulate PLL loop filter noise by cadence spectre? I used 3ord LPF in PLL. As attached figure, dashed lines are resistors noise in LPF and solid lines are output noise after transfer function. Who can help me about LPF noise simulation by cadence (...)

## Sampled Mode of PAC or PXF in Cadence Spectre

Sampled Mode exists in PAC and PXF of cadence Spectre. This mode is similar to "timedomain" mode in Pnoise Analysis of cadence Spectre. The Designer's Guide Community Forum - switched capacitor integrator noise simulation results However I can't get reasonable results for

## PSS + PNOISE and Transient Noise

Hi all, I have several questions which i will describe by topics. All the circuit design is made in Candence using Spectre. 1 - As transient noise introduces noise in the transient simulation, I export the data to Matlab to perform the Jitter (RMS and Peak-to-Peak) calculations. How can I do this in cadence ? 2 - How (...)

## how to get flicker noise for NMOS and PMOS?

Use noise analysis in cadence ADE. Of course, pls use NMOS/PMOS model with the noise.

## Question about pnoise of Charge-pump

I have designd a charge pump of PLL. And I simulated pnoise of Spectre of cadence. The result of charge pump output noise is larger than 100pA at 1KHz. I don't know what is reason about this? Below is my cirucit and simulation result. :cry: Can anyone help me ?Thank you very much

Hi guys, in cadence, i can plot the noise power spectrum with noise analysis. but how can i get the integrated noise information?

I have a current source which charges a capacitor to generate a slop voltage. I want to find out the noise at the capacitor output. Since the capacitor voltage keep rising, there is no steady state. How can i perform the noise analysis?

Hi, I'm simulating a PLL with cadence. Actually I'm driving the system with a vpulse generator, so the reference signal is an ideal square wave. Do you know if is it possible add phase noise to the reference signal? How? Thank you. ps: I've already done behavioral simulation with Matlab. I need to compare the result.

## op-amp noise simulation

Hi guys, I have designed a 2 stage op-amp, diff input and single output. I use cadence spectre simulation tool. All the specs are pretty good. Now I want to calculate the open loop input referred noise of OTA. But I have a question in noise simulation and I dont know if the results I get are correct or (...)

## Plot NF vs QL in Cadence

Does anyone know how to plot NF vs QL in cadence where QL=1/(Rs*Cgg*Ωο)? I did the following simulation steps: 1) I defined QL in calculator window 2) I ran a noise Analysis simulation at 5Ghz (Sweep Variable=Vgg 0->1.2) 3) I Plotted both NF vs Vgg and QL vs Vgg at the same graph windows and then plot (...)

Hi all, after reading all there is to read in this site on transient noise simulation. i steel dont understand how to calibrated the simulation. can someone please write me a step-by-step on how to do it. (a simple example would be great) thanks alot.. Zvika.

## How to calculate signal-to-distortion ratio in Cadence

This is a system problem, not circuit.Therfore, you should model your system with the same conditions and then you may check your signal quality.You can not predict how much PN will be contributed from interferer channel and channel noise. Use system simulation..

## When did Cadence start to support transient noise analysis?

as far as i can remember transient noise simulation was available in orcad 9.0, which was released in 1998. hock

## Noise separation in phase noise simulation

Hi Im doing a phase noise simulation in cadence (using MMSIM70) Im using the option "noise separation" to determine the amount of noise introduced by each instance in my circuit. However, when i compare the total output noise (in the band of interest) with the sum of the individual (...)

## PLL Phase Noise Analysis using Cadence Virtuso

Hi Himali, Go through an attachment to do Phase noise simulation of VCO and PLL. I believe you need Spectre RF to do PSS noise simulation . also, you can go through help manual of cadence.

## how to design phase/freq detector & prescaler in cadence

To simulate PFD and Prescaler you need analog Environment. You need to DC Transient simulation and Phase noise simulation of PFD.

## Noise simulation for NMOS using cadence spectre

Please forward procedure for noise simulation using cadence spectre for NMOS thanks