It could be {Pickle1} and it would still work. I'm just wondering if I can manually change the color settings of the data points. Linear Algebra - Linear transformation question. You've likely already given it a value, eg 1k0. Now lets say that we want to analyze Vo for 10 different types of RL. How to use .step param with more than two parameters in LTSpiceIV, electronics.stackexchange.com/questions/20811/, How Intuit democratizes AI development across teams through reusability. Use MathJax to format equations. I think this message isn't appropriate for our group. This video provides an overview of how to use the .STEP command to perform repeated analysis of a circuit in LTspice. I cannot use Monte Carlo since the cursor information is missing (i.e. The Group moderators are responsible for maintaining their community and can address these issues. Menu On spice directive window, enter the step command as below. Now lets change the values of RL automatically and analyze the results. The .step command causes an analysis to be repeatedly performed while stepping through a model parameter, global parameter or independent source. Interested in the latest news and articles about ADI products, design tools, training and events? The best answers are voted up and rise to the top, Not the answer you're looking for? Here is an example waveform response of an RC circuit, for which the capacitance is stepped through three values. This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. 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}. Thanks for contributing an answer to Electrical Engineering Stack Exchange! Of course, if you know the syntax format, you can also enter it on the "Edit Text on the Schematic" screen. It described a complete circuit, so I extracted just the SCR description. Read more about our privacy policy. To find the maximum power transferred to RL, we can declare RL as a variable resistor but this time we will run the DC Operating .op simulation to get an answer for a list of RL values. Now I want to take that parameter and apply it to my components. In this article, we would like to easily check the analysis results with the LTspice voltage probe. So I wrote a C++ script to create the tables as (long) text files. Disconnect between goals and daily tasksIs it me, or the industry? For more information on how to use the .step command to improve your understanding of a schematic, review the Help Topics in LTspice IV. Here we are simulating RL from 10 to 10k in steps of 100. The PARAM R can be referenced in a component value usng {R} notation. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. into the resistor value field. Check that SINE is selected and DC offset [V]: 0, Amplitude [V]: 2, Freq [Hz]: 500 is input. One way to achieve this is to create a list of desired values to test. Each param should have 3 pairs in it, not three values. We are almost there. After running the simulation we get the following plot with Vo vs RL. Open the edit screen of resistance R2 by "right clicking" the resistance R2 of the schematic with the mouse. To be clear I've used {R5} for my convenience and understanding. 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. This time I set the variable to R2, but anything with alphanumeric characters is fine. In this article, it was placed near source V1. 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. Well for one the table command wants an index, which is X, then a set of xy pairs. I think this message isn't appropriate for our group. Add a .step command via a SPICE directive that specifies the steps for the parameter by a linear, logarithmic or list of values. 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. Note: * is used as a comment in SPICE. I'm just wondering if I can manually change the color settings of the data points. 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. This is useful for associating a name with a value for the sake of clarity and parameterizing your circuits. I am not sure if my question was well understood (yes I did find other similar posts but no applicable answers). You should now see .tran 10m at the bottom of the screen. did phineas and ferb die in a car accident. ltspice step multiple parameters. LTspice is employed for this experiment. Now LT spice knows what you're talking about when you start writing your scripts. Click SPICE Directive on the toolbar to display Edit Text on the Schematic screen. Sim. 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. It is necessary to set the part which changes the parameter in parametric analysis. Step a parameter run number, and from it generate the other parameter values required : Code: [Select] .step param run 1 3 1 ; middle no. 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. This works the same way for all kinds of components and with an external script to create .asc files it can be used as a crutch for LTspices missing monte carlo functonality. What is the point of Thrower's Bandolier? Radial axis transformation in polar kernel density estimate. Subject of the new topic: 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. Refer to the following article for the detailed setting method of the signal source. Thank you. 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). The addition of the curly braces around the variable is important as it tells LTspice IV that X is a parameter. L: Place inductor. In this case, the resistance value is varied from 1k to 10k. In LTSpice the table command really creates a kind of dictionary where you have to specify key value pairs. #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. 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. 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} A .model statement tells LTspice what parameters to use for modeling semiconductors. Would the magnetic fields of double-planets clash? I guess I'll just have to export the data and plot it elsewhere. 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, How to use .step param with more than two parameters in LTSpiceIV. The .param directive allows the creation of user-defined variables. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. posted on January 25, 2022. The .step command is then used to step R through different values. Press question mark to learn the rest of the keyboard shortcuts. is no. Use MathJax to format equations. Google searching for SCR SPICE models, I found a SPICE file on EDN's website. Is there a trick I can use to overcome the 'up to three nested loops' limitation? Are you sure you wish to delete this message from the message archives of LTspice@groups.io? Doesn't analytically integrate sensibly let alone correctly. For example, we can parameterize the capacitance C1 in this simulation with the following modifications to the schematic. If you move the keys up and down in your keyboard you will be able to change between all the different answers. I would like to simulate those three situations and plot them together. He holds a Master of Science degree in electrical and computer engineering from University of California, Santa Barbara. The .step command in this case steps the parameter R through the values 10k, 20k and 30k. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. This could be a case of you get what you pay for. Linear regulator thermal information missing in datasheet. Yes I realized that immediately after sending. - jonk Apr 16, 2020 at 4:28 Analog Devices is in the process of updating our website. Your answer is a simple tutorial on a basic LTspice concept. 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. Then use that parameter's values to control the other. Lets start by creating a user-defined variable in LTSpice. 1: R1 = 1 k\$\Omega\$, R2 = 10 k\$\Omega\$, Sim. 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). Lastly the .op command drives the operation. We comment the first SPICE directive line and uncomment the second line. Parametric analysis analyzes while changing parameters such as resistance, capacitor, inductor, and power supply of electronic circuit. Below is a step-by-step method for how I added one. I have an LCR circuit including voltage sources where I need to sweep more than three parameters (nested sweep) for a transient simulation. The voltage waveforms of OUTPUT appear on the graph pane. The best answers are voted up and rise to the top, Not the answer you're looking for? If you simulate multiple parameters at the same time, LTSpice will compute all possible combinations between those parameters. Welcome to EE.SE! Connect and share knowledge within a single location that is structured and easy to search. Press keyboard letter "T" to show the spice directive. Unfortunately, there's no editing messages but I knew whoever responded would be sure to correct me : ). I'm trying to learn about varying device parameters in LTSpice by setting up a potentiometer model so I can vary the rotation percent and see factors change within the circuit. Subscribe today! In this article, we will explain in detail the parametric analysis(.step) method in LTspice. Are you sure you wish to repost this message? If you want to lay out the schematic editor and graph pane, see the following . This time, set the feedback resistor R2 of the op-amp. The way to do this is with a single .STEP command. If you simulate multiple parameters at the same time, LTSpice will compute all possible combinations between those parameters. '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'. 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. Click on "Simulate" icon bar then "Edit Simulation Cmd" to show the Transient section. 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. As regards your second question, X would be the different indexes that let me access the table's values. The command .step performs parameters sweeps. color of data point should only depend on one parameter, not the other.). 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. For the Nozomi from Shinagawa to Osaka, say on a Saturday afternoon, would tickets/seats typically be available - or would you need to book? Lets build the LTSpice circuit with the original RL value first. LTspice table function. Thankfully, LTSpice generates data when doing a transient analysis with multiple stepping parameters fairly easily. MathJax reference. LTSpice doesn't know what your talking about until you do that bit. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? MathJax reference. This article details how to use LTspice's Waveform Viewer. 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 What sort of strategies would a medieval military use against a fantasy giant? What I mean to do exactly is this: If there were just one resistor whose resistance to vary, then I would just set its resistance to "{r1}" (I use lower case letters to make it a different variable/parameter than R1) and use a command such as: However, since I have to change two parameters (together) two times each, I have read here that (at least on LTSpiceIV) that a workaround to my problem could be using something like this: Upon doing the simulation, I get the following warnings: For some reason, the simulation doesnt "break" if I add one extra element to the table. We are going to work on this exercise in a slightly different order than the one asked by the exercise. 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! Asking for help, clarification, or responding to other answers. Parametric analysis analyzes while changing parameters such as resistance, capacitor, inductor, and power supply of electronic circuit. For multiple lines in the "op" editor window use CTRL+M to keep all params in same textbox. It's important to have all .step commands in one text box. Parametric analysis is performed simultaneously with transient analysis, AC analysis, DC sweep analysis and so on. Here is a list of some hotkeys for creating your schematic: R: Place resistor. Asking for help, clarification, or responding to other answers. Is it possible to step 2 parameters together? Trying to understand how to get this basic Fourier Series. The new topic will begin with this message. 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. After running the simulation, you can iterate through all the answers the same way as we did in Figure 6 and 7. It is provided free of charge by Analog Devices (originally by Linear Technology). Visitors have the right to withdraw their consent. We are commenting the second Spice directive for now. After simulation, the graph pane will appear at the top of the schematic with the default settings of LTspice. If you want to have the values of a resistor near to it, you can also enter (instead of value, when right clicking onto it). run a simulation immediately. http://tech.groups.yahoo.com/group/LTspice/files/%20Tut/Stepping%20to%20the%20max/. The proper directive for your case would then be: and set the value of the resistors to {R1} and {R2} respectively. This multiple value parameter might have values with single quote, such as: abc, efg's, sms dio, 'you's dfd. Besides, the Monte Carlo will take too long and it may 'duplicate' some combinations. Create an account to follow your favorite communities and start taking part in conversations. At LTspice, are there any methods to change the values at once? To know which value of RL corresponds to that particular answer, right click with your mouse on top of it and a pop up window will show you the respective parameter value. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. The general idea (not the implementation) came from the LTspice yahoo group (e.g. https://groups.io/g/LTspice/topic/50201465#60860). In this article, we will explain in detail how to set the simulation command used for the following six types of analysis. flower arranging classes northern virginia. This is not what OP is asking about. I managed to do it using the TABLE function for each of the five variables. When a temperature sweep is used, LTSpice automatically vary the properties of components with respect to desired temperatures. During homework exercises or labs, sometimes you need to analyze the circuits for different components values. 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. Any number of parameters can be made into variables, however LTspice will run simulations on all the different combinations of each value. A place to ask questions, discuss topics and share projects related to Electrical Engineering. The Thevenin resistance is equal to RL for maximum power, in this case Rth = 12. The simulation time varies depending on the size of the circuit. 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. Visitors have the right to withdraw their consent. Click Simulate-Edit Simulation Cmd in the menu bar to open the Edit Simulation Command screen. This time, we set up transient analysis to be performed simultaneously with parametric analysis. Run the simulation and you should get the same results as in Figure 3. In LTspice parameters are variables that can be reused throughout the schematic. Figure 1. For this particular example, the increasing order option goes from 1k to 10k in increment steps of 2k. Visit Stack Exchange Tour Start here for quick overview the site Help Center Detailed answers. Step independent voltage source V1 from 1 to 20 logarithmically with 5 points per octave. From the list of options select the desired one. After placement, right-click ".step" of the mouse to open the ".step Statement Editor" screen. C: Place capacitor. Thanks Andy. vegan) just to try it, does this inconvenience the caterers and staff? 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. Of course, it does not matter if you enter 0.01 instead of 10m without using auxiliary units. 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. 1. communities including Stack Overflow, the largest, most trusted online community for developers learn, share their knowledge, and build their careers. 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). 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 LTSPICE function u(x) is a step function with u(x)=1 for x > 0 and u(x)=0 else. After we finish updating our website, you will be able to set your cookie preferences. LTspice is a powerful and widely used SPICE simulation application. 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. 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. To implement this in LTspice, perform the following steps: Figure 1. If you ever get stuck working with LTSpice, there is a pretty comprehensive set of resources available in the Help menu, including more examples regarding usage. The probe cursor indicates which 'key' (i.e. How can I use it? Found the answer in the group. Something like It is important to understand that if you place the ground reference in a different point you are going to get different results. How to use Slater Type Orbitals as a basis functions in matrix method correctly? On the output graph, add the signals of interest to that graph (in this case Vo) and add a cursor. Refer to the following article for the detailed setting method of transient analysis. Prior to joining ADI, Gabino held various positions in marketing, engineering, operations, and education at Linear Technology, Texas Instruments, and California Polytechnic State University. 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. Steps may be linear, logarithmic, or specified as a list of values. Making statements based on opinion; back them up with references or personal experience. Now lets add a second trace on the graph and add the following SPICE expression, V(vo)*I(R3), to calculate the power across R3 = RL. What LTSpice does is automatically set each step to have a certain color automatically. I've done the trick with the Component Attributes dialogue on both components already. of runs 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. Instead a combination of parameters using SPICE directives needs to be called for help . Thanks for contributing an answer to Electrical Engineering Stack Exchange! 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. Relation between transaction data and transaction id. Using Kolmogorov complexity to measure difficulty of problems? As .tran 10m of dot command appear, place it at an appropriate position. 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. Lets find the value of RL that corresponds to the the maximum power transfer to RL in the circuit from Figure 4. I'm confused, do you want to simulate 3 situations or more? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Whats the grammar of "For those whose stories they are"? 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? Note: To download the simulation files provided in this article, the reader must have LTSpice installed. Gabino Alonso is currently the director of strategic marketing for the Power by Linear Group. Difficulties with estimation of epsilon-delta limit proof, Follow Up: struct sockaddr storage initialization by network format-string. Why does LTspice XOR gate have more than two inputs? 2. The way to do this is with a single .STEP command. AC Op-amp integrator with DC Gain Control in LTspice, How to handle a hobby that makes income in US. If you just want to simulate the 3 scenarios I wouldn't bother doing it with spice. #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. . Firstly, The parameter you wish to vary needs to be designated. Are you sure you wish to repost this message? Stepping Parameters in LTspice IV LinearTechnology 10.8K subscribers Subscribe 486 Share Save 103K views 11 years ago LTspice with with Gabino Alonso, Strategic Marketing. Therefore, for: .step param A list 1 2. Notice Uin could be used as {Uin} in a voltage source or similar and so on. Learn more about Stack Overflow the company, and our products. For instance, plot V in a circuit with R=1 and C=1, then plot V with R=2 and C=2, then plot V with R=3 and C=3, etc. Does a summoned creature play immediately after being summoned by a ready action? Subject of the new topic: Confirm that ".step" of the dot command is displayed as ".step param R2 100 400 100". If you plot multiple signals LTSpice will then plot each trace in a different color but each step for this signal in the same color. The new topic will begin with this message. {R5} then Save. G: Place ground. Groups.io. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. LTSpice for Windows introductory tutorial The circuit It was used in class, and it is a nice example of a circuit that can be handled using node-voltage, mesh-current, or superposition techniques. Click Run on the toolbar to run the simulation. 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). and what would happen then? For this exercise, we have 2 variable parameters, Vs and R, which gives a total of 4 possible solutions. 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. I hope I'm being clear. The ".step" of dot command appears, so place it at an appropriate position. 3: R1 = 1 k\$\Omega\$, R2 = 1 M\$\Omega\$. The .step command has different flavors. Why does it seem like I am losing IP addresses after subnetting with the subnet mask of 255.255.255.192/26? Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? Then use that parameter's values to control the other. .step param B list 3 4. LTspice IV: Using the .STEP Command to Perform Repeated Analysis. Analog Devices is in the process of updating our website. I know I could just export a CSV file and plot them with Octave or Excel, but it would be so much more useful to do it directly on LTSpice. Make sure the "SPICE directive" is selected and enter ".step". 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