Click "SPICE Directive" on the toolbar to display "Edit Text on the Schematic" screen. In any LTspice simulation, varying a parameter in a device or model is just as important as plotting voltages or currents, as it allows you to compare performance and develop your circuit intuition. More than three nested parametric sweeps in LTspice, https://groups.io/g/LTspice/topic/50201465#60860, How Intuit democratizes AI development across teams through reusability. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? Perform parametric analysis using the schematic in the following article. After running the simulation, you can iterate through all the answers the same way as we did in Figure 6 and 7. Figure 1. Interested in the latest news and articles about ADI products, design tools, training and events? I've created a .asc file with basically two resistors in it offering 3 terminals and with their values defined as R* (Val/100) and R* (1-Val/100) based on parameter Val . Are you sure you wish to delete this message from the message archives of LTspice@groups.io? I think this message isn't appropriate for our group. For multiple lines in the "op" editor window use CTRL+M to keep all params in same textbox. In that case, the simulation takes too long, advancing more slowly every time, as it would never end. In any LTspice simulation, varying a parameter in a device or model is just as important as plotting voltages or currents, as it allows you to compare performance and develop your circuit intuition. Andy More All Messages By This Member Andy I #129250 Example:.step param x list 0 1 2 3 4 5.param y={x}or.param y=table(x,+ 0, 5,+ 1, 7,+ 2, 18,+ 3, 22,+ 4, -6,+ 5, 5)or whatever. Especially @afiskon and Ralf B.!If you liked this video be sure to check out my other videos and you can also subscribe to be up to date with all the new ones!If you want to support the creation of more and better videos please consider checking out: https://www.patreon.com/feszelectronics Lets build the LTSpice circuit with the original RL value first. Are you sure you wish to repost this message? But this wouldn't vary the parameters independently. Making statements based on opinion; back them up with references or personal experience. Once the simulation stops, I need to use cursors in Probe to figure out which combination of parameters generates close to a a certain result. In this article, we will briefly introduce the types of analysis that can be performed with LTspice. You are missing a comma in the Vac table after the pair 3,200V. I think this violates the Terms of Service. This time, we set up transient analysis to be performed simultaneously with parametric analysis. into the resistor value field. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Now lets say that we want to analyze Vo for 10 different types of RL. If you move the keys up and down in your keyboard you will be able to change between all the different answers. After running the simulation we get the following plot with Vo vs RL. What is \newluafunction? Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. I have tried setting X to 0 1 2 instead of 1 2 3, but that does not work either. How to pass parameters to subcircuits in LTSpice with the include statement? This article details how to use LTspice's Waveform Viewer. I'm just wondering if I can manually change the color settings of the data points. This is the setting for performing a parametric analysis that changes the variable R2 from 100 to 400 ohms in 100 ohm linear steps. - jonk Apr 16, 2020 at 4:28 You can combine your sweeps by inventing integers that composite them together and then divide them back out using LTspice functions that are available to you. How? Here we are simulating RL from 10 to 10k in steps of 100. run a simulation immediately. Press keyboard letter "T" to show the spice directive. Enclose your variable names in curly braces, in this case {RL}, and then set the SPICE directive .param with the desired valued for your variable name. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Input Name of parameter to sweep: R2, Nature of sweep: Linear, Start value: 100, Stop value: 400, Increment: 100. Visit Stack Exchange Tour Start here for quick overview the site Help Center Detailed answers. In this article, we will explain in detail the parametric analysis(.step) method in LTspice. Open the edit screen of resistance R2 by "right clicking" the resistance R2 of the schematic with the mouse. For this particular example, the increasing order option goes from 1k to 10k in increment steps of 2k. L: Place inductor. Step independent voltage source V1 from 1 to 20 logarithmically with 5 points per octave. Step a parameter run number, and from it generate the other parameter values required : Code: [Select] .step param run 1 3 1 ; middle no. The way to do this is with a single .STEP command. One parameter sweep/step can control multiple component values through expressions. The LTSPICE function u(x) is a step function with u(x)=1 for x > 0 and u(x)=0 else. 1. PSPICE is more suited for this but if you are good at scripting, this should be possible to solve in NGSPICE. For additional information you may view the cookie details. (I'm using the .op command). #ltspiceIn this video I look at how sets of parameters can be stepped at the same time using the .step command together with the table function. For this exercise, we have 2 variable parameters, Vs and R, which gives a total of 4 possible solutions. Define the component parameter with a variable by editing the component attribute (Ctrlright-click on the component) and entering {X} for the Value, where X is a user defined variable name. This could be a case of you get what you pay for. After placement, right-click ".step" of the mouse to open the ".step Statement Editor" screen. LTSpice doesn't know what your talking about until you do that bit. For more information on how to use the waveform viewer, see the following articles: The schematic used for the parametric analysis can be downloaded from the link below. For How to set up detailed transient analysis. What LTSpice does is automatically set each step to have a certain color automatically. The simulation time varies depending on the size of the circuit. The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup, More than three nested parametric sweeps in LTspice. Groups.io. color of data point should only depend on one parameter, not the other.). Like this: .params R=tbl (n, 1,1k, 2,10k, 3, 22k) .params C=tbl (n, 1,1p, 2,10p, 3,22p) use {C} as cap value and {R} as resistor value Then use step command .step param n list 1,2,3 Click to expand. The Thevenin resistance is equal to RL for maximum power, in this case Rth = 12. This video provides an overview of how to use the .STEP command to perform repeated analysis of a circuit in LTspice. In this article, it was placed near source V1. Parametric analysis analyzes while changing parameters such as resistance, capacitor, inductor, and power supply of electronic circuit. Gabino Alonso is currently the director of strategic marketing for the Power by Linear Group. Visitors have the right to withdraw their consent. Your answer is a simple tutorial on a basic LTspice concept. Google searching for SCR SPICE models, I found a SPICE file on EDN's website. 1: R1 = 1 k\$\Omega\$, R2 = 10 k\$\Omega\$, Sim. If you want to lay out the schematic editor and graph pane, see the following article, Display the schematic editor and waveform graph side by side. I need to do three transient simulations with different values of certain resistors (conveniently called R1 and R2) in each. Lets build the circuit in LTSpice. Create an account to follow your favorite communities and start taking part in conversations. Analog Devices is in the process of updating our website. One of those flavors is the ability to include a list of values for your variable name. Its quite a simple implementation that can be used to go trough multiple parameters at the same time.LTspice Tutorial series:EP1-Getting started: https://youtu.be/JRcyHuyb1V0EP2-AC simulation and the Baxandall tone control circuit: https://youtu.be/P_ENvucaZkIEP3-.param and .step directives: https://youtu.be/ARE5nwiHI0QEP4-How to import libraries and component models: https://youtu.be/8V5XabccFaEEp5- Stock example simulations to play with: https://youtu.be/MwfeMjcM4zYEp6- Basics of FFT analysis and .four statment: https://youtu.be/rVAvW1Jh2AEEP7- Dependent voltage and current sourceshttps://youtu.be/Jn8mJG3qeooEp8- Turning a datasheet into a component modelhttps://youtu.be/0smuo8bMRn4EP9- Independent voltage and current sourceshttps://youtu.be/nPZ7vneN3v8Ep10- .wave statement and audio file processinghttps://youtu.be/mdJm-TzrBsAEp11 The effect of temperature on your circuithttps://youtu.be/VzxnNrOMcMoEP12 Modeling a DC brushed motorhttps://youtu.be/Wc4XzTrWSpoEp13- Worst Case, Monte Carlo and Gaussian statistics circuit analysishttps://youtu.be/NdGqboW2VcYEP14 - Digital circuits and logic gates https://youtu.be/JttE2NObDPMEP15- SMPS EMI and electrical noise and filtershttps://youtu.be/QEAzcaiBrpYEP16- Feedback loop simulationhttps://youtu.be/X4yaBwaO1gkEp17 - Verifying Simulation Modelshttps://youtu.be/DSDiIkKQaAEEp18 - Simulating Capacitorshttps://youtu.be/QpWPTolhfEoEp 19 - Simulating Inductorshttps://youtu.be/65fNDRows90EP 20 - Noise simulations https://youtu.be/Dh5XmFXlljIEp21 - Models and Librarieshttps://youtu.be/GUFMfSlD2AMEp22- Voltage and current limited sourcehttps://youtu.be/DnKnuJd3-ecEp23- Measuring Power Factorhttps://youtu.be/qZXOMPxbqh8Ep24 - Modeling a vacuum tube triodehttps://youtu.be/7v9dG1uteAQEp25- Using standard symbolshttps://youtu.be/BFMVujjH0loEp26- Modeling transformershttps://youtu.be/muUwe8X51oYEp27 - Stepping sets of parametershttps://youtu.be/1iOzX91LJ8gSpecial Thanks to all my supporters on Patreon! By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. At LTspice, are there any methods to change the values at once? As regards your second question, X would be the different indexes that let me access the table's values. I need to try a large number of different combinations of parameter values (I have 5 parameters, each of them can take anywhere from 3 to 10 values, for a total number of combinations up to 5000). How should I go about getting parts for this bike? Subscribe today! Refer to the following article for the detailed setting method of transient analysis. Asking for help, clarification, or responding to other answers. The .step command causes an analysis to be repeatedly performed while stepping through a model parameter, global parameter or independent source. You can combine your sweeps by inventing integers that composite them together and then divide them back out using LTspice functions that are available to you. If you simulate multiple parameters at the same time, LTSpice will compute all possible combinations between those parameters. I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. So the table of the values start with the index identifier (here n) then follows the pairs index, value . Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? The proper directive for your case would then be: and set the value of the resistors to {R1} and {R2} respectively. Hope that explanation helps someone else so they're not spending three hours trying to figure out why the code lifted from the examples here may not be working. One parameter sweep/step can control multiple component values through expressions. To learn more, see our tips on writing great answers. Step-by-step explanation lStep 1: Plot for step 6-7 Step 2: Plot for step 7-8 Step 3: Plot for step 9 Step 4: Plot for step 10 Step 5: Plot for step 11 Step 6: Plots for step 12 Step 7: Plot for step 13 Step 8: Plot for step 14 Crossing point: Frequency=336.5 Hz, Magnitude =695.218mV, Phase =44.09 o You can set custom plot colors in the preferences. Yes you can do that (assuming you don't need to dynamically change the voltage within a .tran run) by parameterising the sources and using the table() function to look up the desired values. The probe cursor indicates which 'key' (i.e. We are going to work on this exercise in a slightly different order than the one asked by the exercise. Open the Independent Voltage Source screen by right-clicking the signal source V1 of the schematic with the mouse. In this article, we will explain in detail how to set the simulation command used for the following six types of analysis. It is performed simultaneously with transient analysis, AC analysis, DC sweep analysis, etc. If you just want to simulate the 3 scenarios I wouldn't bother doing it with spice. E.G: In this example, I want to modify two resistors (R5 and R6) so I can see the output of my regulators, assuming that I change the values from 1 ohm to 5000 ohms over 100 steps. Steps may be linear, logarithmic, or specified as a list of values. Connect and share knowledge within a single location that is structured and easy to search. Since (apparently) LT will only allow me to sweep through one variable at a time, I sweep through X and then I try to access the table's values according to the value that X has taken in that step. The Group moderators are responsible for maintaining their community and can address these issues. and what would happen then? Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? During homework exercises or labs, sometimes you need to analyze the circuits for different components values. If you have not drawn a schematic with LTspice, we recommend that you draw a schematic before analysis. How can I use it? The DC operating point, .op simulation doesnt output an answer with respect to time. After we finish updating our website, you will be able to set your cookie preferences. Make sure that the SPICE directive is selected, enter the dot command syntax (.tran 10m in this case), and click OK to place the created dot command. Trying to understand how to get this basic Fourier Series. You should see ".step param R2 100 400 100" at the bottom of the screen. Any number of parameters can be made into variables, however LTspice will run simulations on all the different combinations of each value. Something like this: Paul asked how to step two parameters at once. to get control about its order of execution." So as long it is in the same text box, it will follow the order you write it in. LTspice IV: Using the .STEP Command to Perform Repeated Analysis. Thanks for contributing an answer to Electrical Engineering Stack Exchange! If I don't use the index in the tables I get the same error as indicated in the first post, The working solution was found after reading Would the magnetic fields of double-planets clash? Press question mark to learn the rest of the keyboard shortcuts. For LTspice, use tables to define params. Make sure the "SPICE directive" is selected and enter ".step". You can break that back out into A and B as it executes. You can duplicate this by taking the text at the end of this section and saving it as a file in your LTSpice Confirm that ".step" of the dot command is displayed as ".step param R2 100 400 100". This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. Interested in the latest news and articles about ADI products, design tools, training and events? After we finish updating our website, you will be able to set your cookie preferences. For example, combine parameter A and parameter B into a new parameter, (A*100+B), and sweep that. 3: R1 = 1 k\$\Omega\$, R2 = 1 M\$\Omega\$. posted on January 25, 2022. The list examples detailed above is a different way of achieving the end result required, but it looks like some of the comments are because, as was the case with me, it was not understood that you can't use the component designators without doing the {} thing. Thankfully, LTSpice generates data when doing a transient analysis with multiple stepping parameters fairly easily. You can break that back out into A and B as it executes. Sim. Welcome to EE.SE! Model Statements: Some devices, such as, transistors and diodes require information on the device in order to make calculations. A .param statement can also be placed on a schematic as a SPICE Directive. I've called the parameter Rx: The 1st line defines the steps I want to take as detailed above. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. https://groups.io/g/LTspice/topic/50201465#60860). Does a summoned creature play immediately after being summoned by a ready action? If I'd used {Pickle} then the line would read: The next two lines in the script above tell LTSpice that the parameters for R5 and R6 should follow the steps designated as Rx. LTspice - Resistor value controlled by on/off switch, How can one label a node with more than one name in SPICE/ LTspice. Are you sure you wish to repost this message? I guess I'll just have to export the data and plot it elsewhere. Make sure that the parameter of R2 is {R2}. Note: * is used as a comment in SPICE. Found the answer in the group. In this post (. I hope I'm being clear. The best answers are voted up and rise to the top, Not the answer you're looking for? Making statements based on opinion; back them up with references or personal experience. Press J to jump to the feed. Multiple; T: tera: 10 12: G: giga: 10 9: Meg: mega: 10 6: k: kilo: 10 3: m: milli: 10-3: u: micro: 10-6: n: nano: 10-9: p: pico: 10-12: f: femto: 10-15: . LTSpice: How to start the step of a voltage source at a different time in the transient simulation than t=0s? Note: To download the simulation files provided in this article, the reader must have LTSpice installed. 2023 G: Place ground. If you check the voltage waveform of OUTPUT, you can see that it increases from 2V to 8V each time the parameter of feedback resistor of op amp increases. LTspice can be downloaded for free from here. I'm just wondering if I can manually change the color settings of the data points. Note: For this approach to run without errors, make sure that the size of the list is equal to number of variable parameters. Run the simulation and you should get the same results as in Figure 3. I understand this would be easy to do if the parameters were somehow related (eg: set the value of C={R*constant} or whatever), but what if