Hello, is there a way to set an individual temprature to each transistor we simulate in the circuit?
The reason is we have a temprature gradient on the chip .
Is there a way to do it in cadence virtuoso? so i could see how it affects the performance?
Thanks.
HellO, i have started to use a new technology and i couldnt see in the directoried the FF TT SS corner files in it.
i have looked in the manual and i get only tables with values,no actual directory path of the files in it.
till now i was told specificly where the files are located.
do you know any "standart" manual where its common to specify the path of the corner files in it?
Thanks.
Hello, i saw that MAESTRO is a plotting addon is it a part of ADE EXPLORER?
i cant see the relation between the two.i started to read manual and regarding MAESTRO i only see code.
is there some simple examples?
Thanks.
Hello, i have a realy mistick thing going with copying libraries in cadence virtuoso,
When i copy straight forwart the whole library it gives me a warning that accsess was denied,but when i go into the library and copy it as a single file, then it goes fine.
another problem is it doesnt show in the massage console ALL the files which could not be copied.(which is the much bigger problem,becuase i would have to pass threw all the subdirectories to verify if all files are there)
Is there a way to see which files wasnt able to be copied?
Thanks.
Hi,
I am new to the circuit design and troubleshooting. My project is to design a trans-impedance amplifier using Cadence that can amplify a signal coming from a photodiode. I started out with the regulated cascode configuration as shown in the circuit below. I look at the frequency response using AC simulation and it looks like a high pass (/net 5). The results doesn ot show any gain (transient response), or expected low-pass roll-off in the AC response.
First thing, I looked into the operating regions of the MOSFETs and adjusted the input dc voltage of the Vsin to 0.5 to make sure that the T0, T1 mosfets are in saturation(checked this with the print->dc operating points). Beyond this point, I am not sure on how to proceed and interpret the results to make changes. Any help would be greatly appreciated.
Thanks,
-Rakesh.
Hello , i am trying to extract netlist from a circuit in assembler
I have found the manual shown bellow , however there is no such option in tools in assembler.
how do i view the NETLIST of this circuit?
Thanks.
ASSEMBLER VIEW menu
Virtuoso Version -- IC6.1.7-64b.500.23
Cadence Spectre Version -- 17.10.515
I have a very simple circuit. Please find attached. It is basically a resistor across a port. I run a S-param simulation and can plot the S-params, but unfortunately not the Z-param or Y-param.
Can anyone point me in the correct direction to sort out this problem? The zpm does work in another design environment, but not in the new design environment (a new project). The virtuoso and the cadence-spectre versions match in both the project environments. I am at a loss at what to look for.
Hello,
Would anyone know how to setup a PSS or QPSS simulation with 25% dutycycle clock sources or if such a thing is possible with QPSS.
Fig1 (below) is a snapshot of the circuit I am trying to characterize. This has 4 clock ports each with 25%duty cycle in the ON state. Fig2 below shows two of these clocks.
Each path in the circuit consists of two switches with a low pass RC sandwiched in between. The Input is a 50Ohm port sine wave and the output is a 1K resistor. The output nets of all paths are connected together.
I am trying to determine the swept frequency response from input to output (voltage) when the input is from 500Mhz to 510MHz. The Period (T=1/Fp) of each of the pulses is such that Fp=500MHz. The first pulse source has a delay=0, second has delay=T/4, third delay=2T/4, etc...
I am currently getting it working and seeing the correct result (bandpass response) with Transient but the problem is doing a dft at 500MHz with 10KHz spacings needs at least 100us and takes up a lot of time and disk space.
Many Thanks,
Chris.
Fig1
Fig2
Hello, I have a problem with a certain type of transistor,my hyrarchy has a lot components an sub components and visually inspecting them is very hard.
is there a way like in other cadence layout viewer tools , to enter the name of the component or a NET somewhere and it will focus on it visualy or give the hyrarchy path to it?
Thanks.
Hello,
I am using virtuoso version IC 6.1.7-64b.500.1, and I am trying to follow the Spectre RF Workshop-Noise-Aware PLL Design Flow(MMSIM 7.1.1) pdf.
I could find the workshop library "pllMMLib", but I cannot find PLL Macro Model Wizard, and I attached my screen.
Could you please help me install the module "PLL Macro Model Wizard"?
Thanks a lot!
Hello
The document I referenced is https://filebox.ece.vt.edu/~symort/rfworkshop/Mixer_workshop_instruction.pdf. (This is cadence workshop document)
While following the pxf simulation in the above article, the results are different and I have a question.
My result picture is shown below.
<my result error>
<document result>
<my direct plot>
<document direct plot>
The difference with the documentation is that in the direct plot screen after the pxf simulation,
1.output harmonics-> input sideband
2.Frequency axis: out-> frequency axis: absin
3.The results for port0 (RF port) are also different (see photo below).
4.The frequency values in the box are different.
My screen shows 5G, 10G, 1K ~ 10M, but the document is the same as 1K ~ 10M.
Ask for a solution. Thank you.
Hello, I am trying to use two inductors in my LNA as shown bellow to have a S-PARAM response so i will have S11 with lowerst possible values and tweak them for matching network. However when i ran EXPLORER live tuning with SParam as shown bellow i get no change in the response.
I know that Cgs and Cgd with the inductors having a resonance so by Varying L value i should have seen the change in resonance location,
But there is no change.Where did i go wrong?
Thanks.
Hi all,
What is the most accurate way to simulate the gm of RF transistors (RF stage) of an active mixer (single balanced or Gilbert cell)?
I tried to simulate it with many ways such as:
1. DC annotation (but of course its incorrect due to the switching operation of the mixer)
2. d(i_ds)/d(v_gs) using HB analysis and then taking the value at zero (since it is a DC characteristic). In this way I chose in the simulator results of HB: Voltage, spectrum, rms, magnitude.
3. Using the OP, OPT buttons in the calculator and then extracting the gm of the transistor.
The problem is that each way gives a different value which makes the procedure of designing an active mixer very difficult. In addition, when I simulate the voltage conversion gain of the active mixer and trying to compare it to the formula (2/pi)*gm*RL (either in linear or dB), I get numbers which are way too far from simulations. I understand that I would not get the same results but not different by hundreds percent.
I see in many publications that people are plotting graphs of mixer's gm vs. different parameters and starting to doubt whether the results are correct.
I would appreciate any help,
Thanks in advance
Hello, I looking for reaching minimal NOISE FIRUGE by peaking a combination of the RLC on the output load as shown bellow.
I tried to do it with PNOISE but it gives me an error on the |f(in)| i am not sure regarding the sidebands in my case(its not a mixer)
How can i show Noise Figure and optimize it using my output RLC?
Thanks
Hello, i have made a power gain circle for 30dB,for setting a GAIN we need to set a matching network for input and output inpedance.
but in this Gain circles it shows me only one complex number instead of two.(As shown bellow)
Where did i go wrong with using it to find the input and output impedancies needed to be matched in order to have 30dB gain?
Thanks.
Hi, all
Recently, I meet the simulation error as the picture shows when I simulate my circuit with transient. how can I solve this problem?
thank you~
Hello, i am trying to produce a gain circles on a simple transistor as shown bellow.
i have defined the range from 1 til 30 dB and i dont get any circle just dots in infinity?
Where did i go wrong?
Thanks.
Hello, i have built a matching network of 13dB gain and NF as shown bellow step by step.(including all the plots and matlab )
its just not working at all,i am doing it exacly by the thoery
taking a point inside the circle-> converting its gamma to Z_source->converting gamma_s into gamma_L with the formulla bellow as shown in the matlab->converting the gamma_L into Z_L-> building the matching network for conjugate of Z_L and Z_c.Its just not working.
where did i got wrong?
Thanks.
gamma_s=75.8966*exp(deg2rad(280.88)*i);
z_s=gamma2z(gamma_s,50);
s11=0.99875-0.03202*i
s12=721.33*10^(-6)+8.622*10^(-3)*i
s21=-188.37*10^(-3)+30.611*10^(-3)*i
s22=875.51*10^(-3)-100.72*10^(-3)*i
gamma_L=conj((s22+(s12*s21*gamma_s)/(1-s11*gamma_s)))
z_L=gamma2z(gamma_L,50)
Hello, i need to test the parameter Kf under some conditions in subthreshold.i cannot just plot the OP param,becasue i need to derive it under certain conditions.
Spectre(of Cadence) like BSIM(of Berkley) has developed a method for deriving each parameter in their model.
Is there a way to help me with such manual where i can test in cadence virtuoso the Kf parameter shown in the formula bellow?
Thanks.
Hi All,
I saw the cadence tutorial on measuring IIP3 with 3 tones test (Lets say I have a mixer in the test so two tones are entered in the RF port and one is the LO).
Now, I would like to verify if my receiver meets the bluetooth standard. In the standard it says to enter a signal at -64dBm and two additional signals (interference)
at -39dBm each which placed one k (lets say k equals to one for the example) channels apart and the other 2k channels apart (so 3 signals enter the RF port). These signals cause an intermodulation product to fall
at the frequency of the desired signal. I would like to measure the IIP3 in this case.
Now, I need to enter 4 tones and the IIP3 is measured (based on cadence tutorial) using sweep in the hb.
I do not want to sweep power since I need to enter exact power. I tried to use multi sinusoidal option in the port with exact power but it does not work.
How in general am I be able to check communication standard in this way using virtuoso and measure IIP3?
Can someone please help me?
Thanks in advance!