.param Rf=table(n,1,1.3k,2,1.1k,3,1.2k,4,1k), .param Cf=table(n,1,54p,1,64p,2,64pF,4,64pF), So Rf gets the value of the current index ( defined in the .step directive) color of data point should only depend on one parameter, not the other.). From the list of options select the desired one. In this article, we will explain in detail the parametric analysis(.step) method in LTspice. Input Name of parameter to sweep: R2, Nature of sweep: Linear, Start value: 100, Stop value: 400, Increment: 100. During homework exercises or labs, sometimes you need to analyze the circuits for different components values. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? Note: * is used as a comment in SPICE. The way to do this is with a single .STEP command. Setup the transient command as below. This could be a case of you get what you pay for. Lets use the circuit below as our first example: Lets say we want to analyze the output voltage (Vo) for several different values of a load resistor (RL). Step independent voltage source V1 from 1 to 20 logarithmically with 5 points per octave. Dear Donghoon Park, Thank you for creating such a useful tool! It described a complete circuit, so I extracted just the SCR description. After much thrashing around, I found there are two aspects to this problem that need to be explored. 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. Make sure the "SPICE directive" is selected and enter ".step". Visitors have the right to withdraw their consent. Click SPICE Directive on the toolbar to display Edit Text on the Schematic screen. LTSpice: Step multiple parameters simultanious Uwe Bonnes Aug 1, 2006 Aug 1, 2006 #1 U Uwe Bonnes Guest Is it possible to define the step function so that it influences multiple parameters at once? Note: To download the simulation files provided in this article, the reader must have LTSpice installed. Now, it is set to perform transient analysis for 10msec. The new topic will begin with this message. The command ".step" performs parameters sweeps. Learn more about Stack Overflow the company, and our products. 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 So far, we saw how to apply variable parameters to find current and voltages for components that can have multiple values, and use the .tran simulation command to check the answers in terms of time. In this post (. Open the Independent Voltage Source screen by right-clicking the signal source V1 of the schematic with the mouse. One parameter sweep/step can control multiple component values through expressions. However, with the .step increase order method that can be done faster. L: Place inductor. Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? You've likely already given it a value, eg 1k0. 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. Asking for help, clarification, or responding to other answers. Interested in the latest news and articles about ADI products, design tools, training and events? Figure 1. Something like this: Paul asked how to step two parameters at once. In LTSpice the table command really creates a kind of dictionary where you have to specify key value pairs. . http://ltwiki.org/?title=Undocumented_LTspice#Stepping_a_Model, Powered by SMFPacks Advanced Attachments Uploader Mod. LTSpice: How to start the step of a voltage source at a different time in the transient simulation than t=0s? Lets find the value of RL that corresponds to the the maximum power transfer to RL in the circuit from Figure 4. Finally to find the answer to b), lets have both circuits side to side with RL = 8, LTspice: Using the .STEP Command to Perform Repeated Analysis. Doesn't analytically integrate sensibly let alone correctly. You can change them manually, which will take some time, but you can also set a variable parameter for RL and change its value automatically. which parameter combination corresponds with which waveform). Then use that parameter's values to control the other. Its quite a . The general idea (not the implementation) came from the LTspice yahoo group (e.g. Subscribe today! Subject of the new topic: Press keyboard letter "T" to show the spice directive. 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. Here is a list of some hotkeys for creating your schematic: R: Place resistor. Here we are simulating RL from 10 to 10k in steps of 100. 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. In that case, the simulation takes too long, advancing more slowly every time, as it would never end. Normally, LTspice sets the resistance element parameter to a constant such as R = 10. Open the edit screen of resistance R2 by "right clicking" the resistance R2 of the schematic with the mouse. This command causes an analysis to be repeatedly performed while stepping the temperature, a model parameter, a global parameter, or an independent source. After simulation, the graph pane will appear at the top of the schematic with the default settings of LTspice. The .step command in this case steps the parameter R through the values 10k, 20k and 30k. 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. This time I set the variable to R2, but anything with alphanumeric characters is fine. Subscribe today! Model Statements: Some devices, such as, transistors and diodes require information on the device in order to make calculations. 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: . Analog Devices is in the process of updating our website. MathJax reference. Are you sure you wish to repost this message? In this article, we will explain in detail the parametric analysis(.step) method in LTspice. #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. The new topic will begin with this message. rev2023.3.3.43278. Can I have two (or more) different symbols for the same LTspice schematic? Thanks for weighing in! To learn more, see our tips on writing great answers. Thanks for contributing an answer to Electrical Engineering Stack Exchange! Are you sure you wish to delete this message from the message archives of LTspice@groups.io? Found the answer in the group. For How to set up detailed transient analysis. In this article, it was placed near source V1. D: Place diode. For example, we can parameterize the capacitance C1 in this simulation with the following modifications to the schematic. LTSpice: Step multiple parameters simultanious Uwe Bonnes Aug 1, 2006 Search Forums New Posts U Uwe Bonnes Jan 1, 1970 0 Aug 1, 2006 #1 Is it possible to define the step function so that it influences multiple parameters at once? You should now see .tran 10m at the bottom of the screen. This is useful if you want to maintain a relation or control some indirect physical property of the design like a current or filter property. Lets start by creating a user-defined variable in LTSpice. The .param directive allows the creation of user-defined variables. MathJax reference. and what would happen then? The Group moderators are responsible for maintaining their community and can address these issues. For instance, the forward voltage of a diode will change over different temperatures, the VBE of transistors, the RDSon of MOSFET and so on. Dot command can be created with Edit Text on the Schematic. For example, combine parameter A and parameter B into a new parameter, (A*100+B), and sweep that. This time, we set up transient analysis to be performed simultaneously with parametric analysis. Click Simulate-Edit Simulation Cmd in the menu bar to open the Edit Simulation Command screen. How do/should administrators estimate the cost of producing an online introductory mathematics class? The Thevenin resistance is equal to RL for maximum power, in this case Rth = 12. I cannot use Monte Carlo since the cursor information is missing (i.e. It is provided free of charge by Analog Devices (originally by Linear Technology). Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? Then use that parameter's values to control the other. is no. Refer to the following article for the detailed setting method of the signal source. Subject of the new topic: Can be one line. LTspice table function. After running the simulation, you can iterate through all the answers the same way as we did in Figure 6 and 7. Select Transient and enter 10 m for Stop time. 1995 - 2023 Analog Devices, Inc. All Rights Reserved, LT6108 / LTC6994 Demo Circuit - Energy-Tripped Circuit Breaker with Automatic Delayed Retry (5-80V Input, 500mA Threshold), LTspice: AC Analysis Using The Step Command, LTspice: Using the .STEP Command to Perform Repeated Analysis. LTspice can be downloaded for free from here. Now lets say that we want to analyze Vo for 10 different types of RL. 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. After simulation, when you move the cursor close to the schematic wiring, the cursor changes to voltage probe. Use MathJax to format equations. LTSpice doesn't know what your talking about until you do that bit. 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). In this article, we will explain in detail how to set the simulation command used for the following six types of analysis. The command .step performs parameters sweeps. 'Jonk' may be up to something but still unclear how to perform for example 5x10x4x4x6=4800 independent simulations by 'combining' parameters and then 'breaking them back'. The .step command has different flavors. The ".step" of dot command appears, so place it at an appropriate position. Of course, it does not matter if you enter 0.01 instead of 10m without using auxiliary units. First, prepare a schematic for parametric analysis with LTspice. Are you sure you wish to repost this message? If you've got a resistor R5 on your LTSpice schematic, for example, then Control-Right click over the component to pull up the Component Attributes dialogue box. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. 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. To plot a specific answer, right click on the graph, go to View and select Select Steps. This video provides an overview of how to use the .STEP command to perform repeated analysis of a circuit in LTspice. parameters through use of the Component Attribute Editor. Add a .step command via a SPICE directive that specifies the steps for the parameter by a linear, logarithmic or list of values. The way to do this is with a single .STEP command. Are you sure you wish to delete this message from the message archives of LTspice@groups.io? On the output graph, add the signals of interest to that graph (in this case Vo) and add a cursor. Any SPICE directive with a * in front of it, will not run during simulation. Note: For this approach to run without errors, make sure that the size of the list is equal to number of variable parameters. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. What sort of strategies would a medieval military use against a fantasy giant? 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. Thankfully, LTSpice generates data when doing a transient analysis with multiple stepping parameters fairly easily. To see the results with respect to time, we need to change the simulation type to .tran, transient analysis. If you move the keys up and down in your keyboard you will be able to change between all the different answers. It only takes a minute to sign up. I'm confused, do you want to simulate 3 situations or more? In the "op" command editor you can enter something like this: It steps Imax from 0.1 to 0.3 in steps of 0.1 and computes a resistor value R using parameter Imax, Uin, some assumed voltage drop 0.85.. of a diode. The PARAM R can be referenced in a component value usng {R} notation. 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 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 .step command causes an analysis to be repeatedly performed while stepping through a model parameter, global parameter or independent source. They are defined with the .op SPICE directive " .param <name> = <value> ". The best answers are voted up and rise to the top, Not the answer you're looking for? For the Nozomi from Shinagawa to Osaka, say on a Saturday afternoon, would tickets/seats typically be available - or would you need to book? End result is that my circuit, which other than those two values is in a fixed state, is now complete and, in the example I was trying to get to, I can see the effect on the regulated output. You need to replace this with your parameter designator; put that inside {} brackets, e.g. 2023 LTspice: How can I show multiple probes with waveforms using stepping parameters in different colors? If you simulate multiple parameters at the same time, LTSpice will compute all possible combinations between those parameters. http://tech.groups.yahoo.com/group/LTspice/files/%20Tut/Stepping%20to%20the%20max/. Radial axis transformation in polar kernel density estimate. Is there a single-word adjective for "having exceptionally strong moral principles"? The DC operating point, .op simulation doesnt output an answer with respect to time. Click on "Simulate" icon bar then "Edit Simulation Cmd" to show the Transient section. Trying to understand how to get this basic Fourier Series. Read more about our privacy policy. 2023 Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. It is performed simultaneously with transient analysis, AC analysis, DC sweep analysis, etc. 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. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? I think this message isn't appropriate for our group. Although the .tran of dot command was created from the screen of Edit Simulation Command, it can also be created by Edit Text on the Schematic. parameter combination) was used for each simulation. Groups.io, Is there a way to have LTspice step multiple parameters as a, --- In LTspice@, "dan.friedrichs" . It is necessary to set the part which changes the parameter in parametric analysis. Use MathJax to format equations. Well for one the table command wants an index, which is X, then a set of xy pairs. The .step command is then used to step R through different values. What is the point of Thrower's Bandolier? 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. #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. In this article, we will introduce the "Initial Settings" when installing the latest version of LTspice XVII. 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 . Thank you. In this article, it was placed near source V1. Linear Algebra - Linear transformation question. Example: .step oct v1 1 20 5. The addition of the curly braces around the variable is important as it tells LTspice IV that X is a parameter. To implement this in LTspice, perform the following steps: Figure 1. We are going to find c) and d) first and then find the equivalent Thevenin a), and at last we will find the current in RL for b). When a temperature sweep is used, LTSpice automatically vary the properties of components with respect to desired temperatures. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Lastly the .op command drives the operation. In this article, we will focus on how to set up a independent voltage source for analysis. Google searching for SCR SPICE models, I found a SPICE file on EDN's website. The proper directive for your case would then be: and set the value of the resistors to {R1} and {R2} respectively. Refer to the following article for the detailed setting method of transient analysis. 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. Since we dont have AC signals in this circuit, it is all DC analysis, we are going to simulate the DC operating point of the circuit using the .op simulation command. Read more about our privacy policy. I have tried setting X to 0 1 2 instead of 1 2 3, but that does not work either. The only change that we need to make is to add a set of values for the variable parameter RL. This is useful for associating a name with a value for the sake of clarity and parameterizing sub circuits so . Once you run and view your simulation results in the waveform pane you can review the step information of a particular trace by attaching a cursor (click onto the trace label), using the up and down arrow keys to navigate the steps and then right-clicking onto the cursor to view the step information. If you have not drawn a schematic with LTspice, we recommend that you draw a schematic before analysis. Your control variable you are stepping could be a phase angle or time delay or similar that you input in one or more formulas/expressions to obtain resulting component values or parameters to be applied in the design as {parameter} Something like For additional information you may view the cookie details. Interested in the latest news and articles about ADI products, design tools, training and events? LTspice parametric sweep: how to force the simulator to continue with the next step? 1: R1 = 1 k\$\Omega\$, R2 = 10 k\$\Omega\$, Sim. How can I use it? As regards your second question, X would be the different indexes that let me access the table's values. Add a cursor to the graph and check the value of RL that gives you the maximum power value (the global maximum of the power curve). The result would be three simulation runs with C1 matching each of the values specified in the ".step" statement for each run. Below is a step-by-step method for how I added one. https://groups.io/g/LTspice/topic/50201465#60860). On spice directive window, enter the step command as below. If you just want to simulate the 3 scenarios I wouldn't bother doing it with spice. 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! Connect and share knowledge within a single location that is structured and easy to search. By clicking Accept All, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. into the resistor value field. Here is an example waveform response of an RC circuit, for which the capacitance is stepped through three values. By clicking Accept All, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Click Run on the toolbar to run the simulation. Press J to jump to the feed. I hope I'm being clear. Can I specify that it should only change color when stepping one of the parameters? There are two ways to examine a circuit in LTspice by changing the value for a particular parameter: you can either manually enter each value and then simulate the circuit to view the response, or use the .step command to sweep across a range of values in a single simulation run. Thanks for contributing an answer to Electrical Engineering Stack Exchange! Linear regulator thermal information missing in datasheet. By computing 1-u(Temp) the temperature coefficient tc3 is effective only if Temp < 0 C. Making statements based on opinion; back them up with references or personal experience. I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. Step a parameter run number, and from it generate the other parameter values required : Code: [Select] .step param run 1 3 1 ; middle no. For multiple lines in the "op" editor window use CTRL+M to keep all params in same textbox. this is how I roll it in 1 run (same method as what mr stilltrying said). I would like to simulate those three situations and plot them together. Welcome to EE.SE! Thanks Andy. Check that SINE is selected and DC offset [V]: 0, Amplitude [V]: 2, Freq [Hz]: 500 is input. Whats the grammar of "For those whose stories they are"? Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. As .tran 10m of dot command appear, place it at an appropriate position. I'm trying to get the results of simulation in "DC operating point" mode with a few varied (.STEP) parameters (example b. LTspice IV: Using the .STEP Command to Perform Repeated Analysis. For this exercise, we have 2 variable parameters, Vs and R, which gives a total of 4 possible solutions. One way to achieve this is to create a list of desired values to test. run a simulation immediately. Create an account to follow your favorite communities and start taking part in conversations. The LTSPICE function u(x) is a step function with u(x)=1 for x > 0 and u(x)=0 else. I'm just wondering if I can manually change the color settings of the data points. Thanks Ian.M, i tried it but cant seem to get it to work. "You can make nested .step loops up to 3 levels. How to use Slater Type Orbitals as a basis functions in matrix method correctly? LTSpice, command line execution does not generate .raw file CPaul962 on Jan 28, 2020 I have a schematic consisting of a network of resistors, MOSFETs and DC voltage sources which I would like to do DC simulations of. Then, in the waveform viewer, you can have three plot panes each showing only the result for each step by specifying "@" for the displayed value. There are two ways to examine a circuit by changing the value of a parameter: You can either manually enter each value then re-simulate the circuit, or you can use the .STEP command to sweep across a range of values in a single simulation run and produce a side-by-side comparison. To learn more, see our tips on writing great answers. 3: R1 = 1 k\$\Omega\$, R2 = 1 M\$\Omega\$. Parametric analysis analyzes while changing parameters such as resistance, capacitor, inductor, and power supply of electronic circuit. In many practical situations, a circuit is designed to provide power to a load, and sometimes it is desirable to maximize the power delivered to that same load (normally called RL). So I wrote a C++ script to create the tables as (long) text files. Difficulties with estimation of epsilon-delta limit proof, Follow Up: struct sockaddr storage initialization by network format-string. In addition, since the schematic was prepared here, if you want to start analysis immediately, download it by clicking the link below. G: Place ground. For example, combine parameter A and parameter B into a new parameter, (A*100+B), and sweep that. For additional information you may view the cookie details. It is performed simultaneously with transient analysis, AC analysis, DC sweep analysis, etc. Make sure that the parameter of R2 is {R2}. This is useful for associating a name with a value for the sake of clarity and parameterizing your circuits. Visit Stack Exchange Tour Start here for quick overview the site Help Center Detailed answers. Your control variable you are stepping could be a phase angle or time delay or similar that you input in one or more formulas/expressions to obtain resulting component values or parameters to be applied in the design as {parameter}. did phineas and ferb die in a car accident. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. So the table of the values start with the index identifier (here n) then follows the pairs index, value . We comment the first SPICE directive line and uncomment the second line. communities including Stack Overflow, the largest, most trusted online community for developers learn, share their knowledge, and build their careers. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. LTspice - Resistor value controlled by on/off switch, How can one label a node with more than one name in SPICE/ LTspice. Any number of parameters can be made into variables, however LTspice will run simulations on all the different combinations of each value. 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.