Dc operating point cadence and the transient operation point should be a fixed point, the same meaning with the DC point. I wonder how I can save the DC operating points in the output window and have the valued displayed after I run simulations for different corners. it is like the dilemma of chicken and egg. • In the window that pops up, select dc to choose a DC analysis. Updated information: when I use Results->Print->DC Operating Points in the Virtuoso ADE, I can see the DC Operating Points in the "Results Display Window;" as such, it appears that the issue is not design-kit-related, as the data exist but are not displayed on the schematic diagram. Hi all. Aug 7, 2020 · However, if you plot the operating point waveforms, you get a value versus the swept variable. First of all you should specify the DC voltage where you want to extract small signal parameters of the transistor. So, what are the definition or how these parameters are calculated in these regions? It makes sense to define ron in When you do this, it should have opened the schematic in a tab, as well as opening the "Results Display Window". The first test runs the DC analysis and measures the gm (which you should be able to retrieve using a calculator function such as OP("/M0" "gm") and have as a named output (called, say M0_gm), or even to calculate the resistor value you need to compute. From the Results menu in ADE select Print -> Operating point, then select the transistor which parameters you want to see. On relaunching Cadence or for different schematic, I have to setup again. Thanks in advance I've searched but I haven't found it. Is there a way to annotate the DC operating point of the subcircuit component in the schematic or display it in the info balloons? May 8, 2023 · See this post (the second bullet point). 01 save M1:d M1:gm (I chose a fine step for the dc sweep to minimise the difference due to the step in the derivative), the I get: which as you can see is very close. Ids = 100. The simulation starts from the converged solution, and iterates (hopefully) to convergence. A dc sweep with dc operating point enabled in ADE-L (or even just straight up spectre from the command line) only reports dc operating points (like gm, gds, etc) at the start point. 8-64b. You also learn various convergence methods to overcome The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. Plotted on a chart, the DC operating point is the intersection of the base current and the DC load line. 73 cggbi (F) Intrinsic gate capacitance. Team SimTech . However, the same dc operating point is used for every dc step. First of all, the naming of the files doesn't imply any meaning - it's just a matter of what ADE calls various files by default. scs and loading this in the model libraries setting of the ADE and getting the dc operating points in the simulation. to inject signals or add loads, or potentially add test bench-level components inserted into the hierarchy. How can I can expand the list to show more parameters of the DC operating points? Thank you in advance. For instance, for displaying the operating point parameters after a DC analysis I always have to change the annotation settings for my active devices through the View->Annotations-Setup options. Diodes are non-linear devices. However, as the OTA that makes part of LDO is internally supplied by the output voltage, the simulation will never turn on the OTA and it will find a very stable point of operation in 0V. I am not sure on why this discrepancy is occuring. For example, CGG = cgg + cgsol + cgdol + cgbol, CGB = cgb + cgbol, CDD = cdd + cgdol + cjd and for the junction or depletion capacitances such as CDB from hand calculation Jul 29, 2020 · Version: ICADVM18. Thank you. In my simple simulation test, I am connecting one NMOS transistor with a fixed VDS and sweeping the VGS. How can sp simulation with old dc operating point - RF Design - Cadence Technology Forums - Cadence Community Jul 10, 2021 · The DC algorithm iterates to a solution, then the resistors/current sources are removed. 23 and trying to have DC voltage annotation to display on my schematic after DC operating point simulation via the “Results -> Annotate -> DC Node Voltages”. scs file and sourced it in Setup -> Simulation Files -> Definition file: Aug 18, 2023 · The sweep in the DC doesn't matter (sorry Shawn - also when you do a DC sweep it does not do an operating point analysis at each sweep point, or rather it might, but it doesn't save it). results > annotate > dc operating points . Everything works fine for 0. When I chose to print DC Operating Point of the MOSs used in my design, I came across this parameters viz, "Vsat" and "Vdss". 1234567891234 nA). 01528 A/V2 and NMOS-0. If I need to use a loop would you please let me how to write it. There's also this: How to save and plot operating point parameters for Spectre simulator from ADE Explorer/Assembler. Before it, I can see the DC operating parameters when I go to Tools->Result Browser in the ADE. Jan 30, 2020 · The "id" is an operating point parameter which is what you would have get from a DC operating point with everything biased at the voltages at that instant of time, and the capacitors would have no effect in that case. First of all, does your DC start from precisely the same conditions as are in place at the end of the transient (in other words, the value of all inputs and also the values of the thing you're sweeping must correspond to the value The simulation would be a dc operating point or a transient where I specifiy the time for printing. 080, cadence_spectre 19. 8-64 bit. The question is that which command can print all DC values into the file (instead of calling function "fprintf" for each one by one like above)? In short, I need a such command fprintf(p,"%f", outputs()). Yes, you can define a nodeset using a condition such as you've given. 뒤에서 좀더 설명합니다. 000003e-6 M1:id = 800. 500. Happy learning! Dec 16, 2021 · then scroll to the Operating Point Parameters section, you'll find: 17 ro (Ohm) Common-emitter output resistance. 72 cssbi (F) Intrinsic source capacitance. " May 7, 2015 · When I run a DC simulation, the DC operating points are nicely annotated at the toplevel, but not in any of the subcircuits (down the hierarchy). Sep 8, 2020 · In this video you will learn the dc load line and operating point of transistor. I am running a very basic Dc operating point info simulation on my circuit. Or a DC before a transient (if you give a readns, say), or for the DC operating point at the beginning of a sweep. Hi all, I run a DC sweep simulation on ADE and I would like to plot some of the DC operating point parameters of my schematic (such as vdsat of the transistors Use of DC operating point parameters in calculations and plots - Custom IC Design - Cadence Technology Forums - Cadence Community Length: 1/2 Days (4 hours) Become Cadence Certified This course is part of the Virtuoso® Spectre® Pro series and focuses on the DC Analysis algorithms of the Spectre Circuit Simulator and its corresponding analysis options. Spectre outputs number (0-4) in a rawfile. Is there a way to control marked field property from skill code ? I need to be sure that it is set on before continuation of further skill calls. On setting up the dc analysis I check the DC operating point box. 그리고 Save DC operation Point와 Enabled에 Check가 되어있어야 합니다. i don't know how to observe the operation region during the simulation either, but i suggest you to annotate the transient node voltage, and you can calculate it by hand. Regards Mar 8, 2012 · In cadence DC analysis operating point there are two parameters ron and rout. DC Operating Points Setup analysis to extract small signal parameters of the transistor. HiI go through DC operating point analysis on Cadence. I can do this in the ADE window, but do not want to see it graphically. Once the simulation finishes, I save my needed operating point parameters in oceanscript to take it to MATLAB for plotting. I got the satisfying result indeed if I set Vtest to 1V and print the DC operating point after running a DC simulation (as shown in the picture above). A new menu should appear on the side and from that, choose "DC operating point. With this video you will learn to run a DC simulation to find device threshold voltage, capacitance, etc. Jul 11, 2024 · Hi. But Now I am getting the region displayed as numbers "0,1,2" Can someone please tell how to get the operating region names? Thanks I am new to cadence. I am trying to simulate in ST Micro 40nm CMOS Technology using cadence 6. I am using IC6. You can then use the OS function in the calculator to access the operating point parameter versus sweep. Hi prashu, have you solved your problem? it seems that a dc analysis should be excuated before the transient analysis. Nov 10, 2021 · I run several different analyses, i. It seems that the simulator determines the DC operating point separately for each analysis. Do you know if there's a bindkey to annotate the DC Operating Point on the schematic? I'm working with Cadence Virtuoso 6. Due to this I am unable to sweep any dc op parameters, and I have to manually do the print dc operating point for every simulation, and this is becoming time consuming. m1:all' for transient simulation. I want to know the parasitic capacitance of the NMOS. Jan 4, 2020 · You've presumably set up the saving of operating points via Outputs->To be saved->Select OP Parameters (otherwise the OS function wouldn't be there - this means "Operating point for Sweep" (where Sweep is DC sweep), so you would need to use either:. ( top level ; resonably big) Iam using spectre-X with preset LX option along with APS-DC enabled in the advanced options tab. Any thoughts? Thanks. - Use the browser to select the Measurement Component, i. , ac, noise and dc, during a Spectre simulation. Andrew If you include this set of discrete devices in the same test bench as your original parametized stack device and provide it with the same external voltages, it may provide some added insight into how consistent the DC operating point information of the parametized cell is with its discrete counterpart. It worked well in AMS 0. 237 I followed the instructions for measuring operating point parameters for stacked Jul 14, 2023 · About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright Jul 21, 2023 · First thing to check is whether M50 and M38 are the same type of transistor. cds equals cdsbo while cgs does not equal to cgsbo. Initially the Results Display Window will be blank, but the schematic window should be prompting you to click on nodes (if it's for DC Node Voltages) or click on devices (if it's for DC Operating Point). Running a DC operating point along with the sparameter simulation makes it take longer and the spar sim calculates its own operating point to measure the sparameters so it would be great if I could use it's operating point rather than simulating it twice. I see that ron and rout are defined for all operating region (sub-threshold, triode, saturation). After choosing DC Operating Points, in your schematic you need to click on the transistor whose DC parameters you want to analyze. dc dc dev=Vg start=0 stop=5 step=0. The save is only needed normally if you are wanting to plot operating point versus time or versus a dc sweep. Consider I sweep VDS for single NMOS transistor with a constant VGS, I am unable to get the DC Operating Point. These are the DC operating point parameters for the intrinsic capacitances of the Bsim3v3 MOS model (Spectre implementation). You could change the Component Parameter to DC Operating Point, but I would advise making life easier for yourself and just annotating the DC operating points (Results->Annotate->DC Operating Points in ADE) as that is then less work. Mar 17, 2022 · Consequently, there is only one point on the dc load line where the diode voltage and current are compatible with the circuit conditions. So if you do a DC operating point, node sets are used for that. - For DC operating point measurements, select OP_DC under Measurement; to plot the dynamic value of a measurement during time domain simulation, select OP_DYN. Setup Output Traces • In Virtuoso Analog Design Environment window, select Outputs => to be plotted => Select I am trying to plot different operating point components of the MOS transistor (gm, region, vth,etc). You can also Print DC Node Voltages and have them show up in the schematic window. Jan 31, 2005 · cadence operating region 4 Hi vbhupendra and rfsystem, I use ADE 5. I would like to make plots of gm over Id and I'd like to do that from a SKILL/OCEAN script. The first point is that we need to measure the short circuit current gain so ideally the output terminal, collector [drain] of the transistor will be connected to a power supply. My problem is that I can only have access to the gm value for the bsim model for the DC operating point, not for all the values. Only limited number of results are printed as shown below: I would expect to see much more dc info cadence cgs cggbo When choosing DC analysis, first make sure you check the box that says "Save DC operating point. I would like to save all transient operating point parameters and then plot them with time. Jun 9, 2016 · Vg (g 0) vsource dc=2 Vd (d 0) vsource dc=5. I hope this provides a bit more insight david73 I am using Cadence Virtuoso version 6. Apr 17, 2019 · You can however save operating point data versus transient should you want by using Outputs->To Be Saved->Select OP Parameters - you can then choose which operating point parameters to be saved for certain devices - and do that over time or over a dc sweep. It explains DC analysis and DC sweep in cadence with examles I also know if I use outputs() command, all DC values will be printed out. the specific value on the element of interest. We use annotations for op points. 35um, 130nm & 180nm. I have searched for various options, but could not find any flag to make that happen. I remember getting it by setting up View> DC annotation> Setup > selecting DC operating region > Display > region. zakir The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. hoose analysis as the analysis you want to run (on’t forget to check “Save Operating Point”): Feb 25, 2021 · The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. I hope this helps identify the cause of the issue. " Hence, the "starting" point for a final DC operating point is influenced but the value(s) of nodeset(s) you choose. e. I'm sweeping the linear regulator input voltage on DC from 0V to maximum expected Vin. For bsim4, recent versions of the documentation have added links between the operating point parameter lists (at the end of the chapter on bsim4 in the document Quek mentioned) to the appropriate equation (where relevant). 0. The next point is that we need to calculate the current gain of the transistor. " After running the analysis, go to the "Results" menu in the Analog Environment and put your cursor over the "Print" item. If I turn on a DC operating point analysis, and a short transient and leave everything else as default in ADE, it netlists as: dcOp dc write=" spectre. When I run the dc simulation and want to check the dc operating point of the transistor. 18-um CMOS model in my work (Cadence, Spectre) and I am wondering about how to figure out the total parasitic capacitances of a transistor. Regards, Andrew. It's a bit overkill to use deepprobe just to monitor an internal node in the hierarchy; the original intention of this component (which was created by me in the first place) was to allow you to make connections down in the hierarchy - i. Info can also be found in the Spectre Circuit Simulator Components and Device Models Reference manual, near the end of the chapter. Tool Version : ICADVM20. 10. Mar 30, 2022 · The DC Operating Point of a NMOS is shown below. Dear Andrew, We used the method of print DC model parameters and found the mobility of PMOS-0. Since now I am using a BSIM3. 1 nA? Aug 18, 2014 · This is a very basic tutorial for beginners. Regards May 17, 2021 · To see DC operating point, I did DC simulation, and it seemed like the values settled on wrong point. Mar 14, 2024 · R0 here is 300k, and I was expecting to get a 100k equivalent resistance (300k-200k=100k) at node Vtest. as well as the other parameters. I believe ft and self_gain may be added by us, but I'm afraid I don't know the details. ) Jan 8, 2021 · The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. May 5, 2016 · How do I see the operating region names like "active, saturation" in cadence for MOSFET. It is exactly like annotating the operating point. Cadence Design Apr 21, 2021 · When I annotate the DC operating point in the schematic, the number of decimals displayed is very high (e. 35um, UMC 130nm, but not in ST 130nm :-( Jul 9, 2007 · cadence dec operating point You can see these parameters for a given operating point using the Print command. While we calculate new dc operating point for every dc step we could use them one after another for following dc steps as in the example above. You have however selected the save operating point checkbox which means it will save the DC operating point and then do a DC sweep. Hi all, I run a DC sweep simulation on ADE and I would like to plot some of the DC operating point parameters of my schematic (such as vdsat of the transistors Use of DC operating point parameters in calculations and plots - Custom IC Design - Cadence Technology Forums - Cadence Community Aug 6, 2020 · Dear Pecman, I think the issue you are experiencing might be due to the fact that you have run multiple corners in Assembler. Some random thoughts until I get back: One thing I forgot to mention was that if I run a DC operating point sim and enable DC operating point annotations then the final resistance value I'm after is annotated on the resistor - my original post was because when I ran a transient sim and enabled transient operating point annotations the resistors didn't show any annotations at all. Aug 28, 2020 · See Chapter 8 on DC Operating Point output. STEP 13. use following 3 expression to get the gm/id plot. Jul 8, 2020 · However, when I use the print dc operating points, then all the parameters are displayed. 7-64b. (Save DC Operation Point는 소자 특성 보기 위한 Option입니다. 8, cadence_icadv 18. Do a 'spectre -h bsim3v3' from the command line: 71 cddbi (F) Intrinsic drain capacitance. any way HI, I am using virtuoso 6. 5 version. scs' file ? Also i would like to know to determine other operating point parameters in transient as well as DC simulation in hspice, like how we do in 'save M3. 02118 A/V2, Which contradicts the basic fact the mobility of NMOS is greater than PMOS. virtuoso设置显示静态工作点信息，以及修改symbol来显示更多需要的参数, 视频播放量 3937、弹幕量 1、点赞数 70、投硬币枚数 43、收藏人数 162、转发人数 32, 视频作者 董大侠想躺平, 作者简介 一个从ader转型为designer的人，ic设计讨论群qq715687140，相关视频：第三季-virtuoso 的查找替换功能简单介绍 Oct 2, 2019 · At the Q-point, we see a steady-state DC voltage or current at a specific terminal with no applied input signal. When I use ADE, after the DC sim, I can choose "Annotate - DC operating points", then the net voltage will be displayed in the schematic. Andrew. 1 -64b. (4) Add dc voltage sources to each pin of the transistor in the new schematic using values from step 2 (5) Run a DC sweep on Vds (Vgs, Vbs is fixed to operating point value) for the new schematic (6) Calculate Rout=deriv(Id) (7) Create arbitrary definition: vdssatxxx is the Vds when Rout is degraded 50% from the value from Vds=Vdd/2 Mar 6, 2017 · 우측의 AC, DC, Tran 모양의 아이콘을 클릭해도 됩니다. On the transient options form, there's a field called "infotimes" - specify the times at which you want it to output the dc operating point data. dc" maxiters=150 maxsteps=10000 annotate=status Apr 13, 2021 · Hello everyone, I am using Cadence 6. When a MOSFET functions as an amplifier, the transconductance of the device is a function of the Q-point. The first simulation was performed using the netlist & run within Explorer. Nov 29, 2021 · Hi all. The simplest way of finding out (rather than diving through all the model files) is to do a single DC operating point, and then look at the operating point results in the results browser, and see what the instance name there is called. You should contact customer support if you need to know this. 1. It's possible that one of them is modelled as a subckt model, and the CDF may have only been set up to expose a limited set of operating point parameters - whereas if the other device is directly modelled it may expose all of the operating point parameters. I saw some cases on community forum and inserted below lines to my save. 3 0. Sep 20, 2019 · You did not do step 1 that I listed above (annotate the DC operating points as normal first). Type select Nonlinear > Op Point. 33 release, and I can print the DC Operating Point but I cannot use this DC Operating Point annotation feature, so I am wondering whether this feature depends on ADE version and/or spectre model. Jul 16, 2008 · It is defined as the unity gain frequency of a transistor’s short circuit current gain. in the file saveop. The transconductance (gm) is the slope of the line tangent to the active curve at the operating Q-point. My guess is that they are just aliases for the original parameters, which you could probably confirm with a little experimentation. But there are cgs, cgsbo, cds and cdsbo. There is dc blocking at the input, so each time, the dc is the same, only mathcing component change for S11. 4. Hello, After running DC simulatin, when i do Results-> Annotate-> DC operating point it is showing the following warning *Error* eval:undefined function Pls help Re:Annotate DC Operating point - Custom IC Design - Cadence Technology Forums - Cadence Community 2 region=triode Estimated operating region. (Results were not reasonable. 6 and I am trying to save BJT operating point parameters such as gm, ft, beta etc during a DC sweep. I am wondering if there is a similar way to do that with transient analysis. You also learn various convergence methods to overcome Nov 15, 2022 · The DC option "force" must be enabled to use the initial condition file. and i included one scs file with "save NM0:all", i can got gm, id and gmoverid by dc simulation. In Cadence Virtuoso (IC 615): How can the number of dc operating point values to be displayed be increased? That is, in my schematic, when I do Edit ->Component Display, there are only 4 drop-down boxes that can be selected for the PMOS component; how can I increase the number of drop-down boxes? Is there a way to get the DC solution by running an sparameter analysis alone? I am using APS for this simulation. Topics Covered:• Definition of a Output Characteristics of the Transistor• DC Length: 1/2 Days (4 hours) Become Cadence Certified This course is part of the Virtuoso® Spectre® Pro series and focuses on the DC Analysis algorithms of the Spectre Circuit Simulator and its corresponding analysis options. DC operating point for one step is closer to the ideal for following dc step, while initial tran operating point may not. Andrew May 21, 2020 · A DC operating point, also known as quiescent or Q point, refers to the state of the transistor when no input current is applied to the component. The transient directory doesn't have the needed info. When I run the DC operating point there is limited parameters that I can show on the schematic, in my case only 4 as shown in the image below. But for 28nm, I don't get the DC operating points parameters. ) However, when I did sweep simulation (sweep variable was temperature, which should be almost non-relative to the results), I found DC convergence result goes to correctly as simulations goes on. I am quite new to cadence and almost completely new to SKILL, so please forgive if some questions have obvious answers. Hi all, I have a question to ask about BSIM model, I hope it will not take too much time for you to answer this question. • Choose Save DC Operating Point and press OK. There is a option to save the setup. 2. 000003e-6 The Cadence Design Communities support I am currently using ICADVM20. How to feed this command ? Should it be done like spectre in 'saveop. Aug 1, 2022 · I can customize operating points displayed on schematic temporarily using Annotation Setup. Hence, the reason the Assembler menu items "DC voltage and DC operating point" are greyed out is that there may be multiple DC voltages and DC operating points and it cannot annotate multiple values on the schematic. In other words, this operating point (Q point) is the intersection where the optimum forward voltage and forward current converge, and it is also the point where the diode operates at its optimum. (attached screenshots). So, two questions, really: - Is it possible to re-use the DC operating point found during, for example, the dc analysis, for the ac and noise analyses? This depends on the model you're using. You can then annotate the "transient operating points" from any of these times after the simulation, or access them via the results browser. My transistor is defined as a subcircuit (a traditional subcircuit, not an inline subcircuit). 5. You also didn't explain that you were trying to utilize the final operating point of the transient to start the DC. It is time consuming having to do the same for each new schematic, so I would like to change the default annotation options for these devices so that Sep 6, 2020 · Hello, In DC simulation it is possible to save DC operating point parameters to determine extrinsic and intrinsic capacitances. I tried the solution here but that doesn't work. The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. Note there's no need to do the save if you're normally just looking at dcOp (operating point) data from an operating point analysis. Hi Ronen, The simplest way to do this would be to have two tests. Or they're used for the DC before an AC analysis. Possible values are off, triode, sat, subth, or breakdown. Aug 13, 2022 · hello . - Under Meas. 1-64b. g. In this class, you learn how the Spectre simulator uses the DC Algorithm and reaches a DC operating point solution. Apr 9, 2016 · As you can see the transient operating point for id at the time zero: DC : M0:id =800. Sep 17, 2019 · The list above is not exhaustive; however, it does serve to illustrate that diodes are widely used in many electronics applications. 여기서는 DC를 설명할 예정이기에 DC를 선택합니다. How could I modify the decimals displayed to have only one decimal (e. This is an old answer to saving DC operating points. I'm interested in being able to *quickly* simulate some device small signal characteristics versus some parameter (design variable, temperature, etc). Apr 11, 2018 · Hello, I am using cadence 6. For many of these, there is a best state or operating point at which we want the diode to function. On page 21 it states: "Note: The Spectre simulator ignores Initial Conditions of all types in the DC Operating Point analysis and the AC Operating Point analysis unless the force option is set in the DC and/or AC options forms. Hi, I just want to do the gm/id plot, by following circuit. Setup Output Traces • In Virtuoso Analog Design Environment window, select Outputs => to be plotted => Select Dec 31, 2020 · The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. Determining the Operating Point of a Diode. sjfaob cccavgl jjovt jpz vvcd jenb nns kksojczl heqw faao