The general idea (not the implementation) came from the LTspice yahoo group (e.g. Refer to the following article for the detailed setting method of transient analysis. If you simulate multiple parameters at the same time, LTSpice will compute all possible combinations between those parameters. parameter combination) was used for each simulation. Read more about our privacy policy. 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). The problem was that the size of the tables (given by the number of total parameter combinations) was prohibitive to write by hand. On spice directive window, enter the step command as below. I need to do three transient simulations with different values of certain resistors (conveniently called R1 and R2) in each. ltspice - How to use .step param with more than two parameters in In LTSpice the table command really creates a kind of dictionary where you have to specify key value pairs. The ".step" of dot command appears, so place it at an appropriate position. 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. It described a complete circuit, so I extracted just the SCR description. We are almost there. LTSpice for Windows introductory tutorial - garytuttle.com Another use of variable parameters can be to find the maximum power transferred to a load. In this article, it was placed near source V1. The way to do this is with a single .STEP command. Instead a combination of parameters using SPICE directives needs to be called for help . To see the results with respect to time, we need to change the simulation type to .tran, transient analysis. I think this violates the Terms of Service. 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. 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. The command ".step" performs parameters sweeps. The Group moderators are responsible for maintaining their community and can address these issues. is no. LTSpice: Step multiple parameters simultanious | CO.UK edaboard.com Are you sure you wish to delete this message from the message archives of LTspice@groups.io? I am not sure if my question was well understood (yes I did find other similar posts but no applicable answers). 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. 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. Any SPICE directive with a * in front of it, will not run during simulation. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? To learn more, see our tips on writing great answers. In this LTspice requires setting of the signal source when simulating. The .step command has different flavors. Is there a trick I can use to overcome the 'up to three nested loops' limitation? 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. - jonk Apr 16, 2020 at 4:28 For additional information you may view the cookie details. Press keyboard letter "T" to show the spice directive. Use MathJax to format equations. After we finish updating our website, you will be able to set your cookie preferences. Create an account to follow your favorite communities and start taking part in conversations. Its quite a . I found most of the solution for passing multiple value to stored procedure is to create a user defined function to put the string to a table, then grab the value from table to stored procedure. Analog Devices is in the process of updating our website. If you move the keys up and down in your keyboard you will be able to change between all the different answers. 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. LTspice@groups.io | Stepping multiple independant parameters So I wrote a C++ script to create the tables as (long) text files. spice parameter sweep | All About Circuits ECE 202 - Tutorial: LTspiceParamterSweep - Min H. Kao Department of LTSpice: How to start the step of a voltage source at a different time in the transient simulation than t=0s? Can be one line. which parameter combination corresponds with which waveform). 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! rev2023.3.3.43278. ltspice - Create .step list based on another parameter - Electrical Visitors have the right to withdraw their consent. Press question mark to learn the rest of the keyboard shortcuts. We are commenting the second Spice directive for now. Firstly, The parameter you wish to vary needs to be designated. Now lets say that we want to analyze Vo for 10 different types of RL. 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. 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. Whats the grammar of "For those whose stories they are"? Then you use .include and .step param and the TABLE function in LTspice to perform the sweeps. Managing temperature in LTSPICE | Electronics Forums I'm confused, do you want to simulate 3 situations or more? Click SPICE Directive on the toolbar to display Edit Text on the Schematic screen. Can I specify that it should only change color when stepping one of the parameters? Lets build the LTSpice circuit with the original RL value first. Another way to simulate a set of values at the same time is to use the increasing order option of the .step command. What LTSpice does is automatically set each step to have a certain color automatically. The PARAM R can be referenced in a component value usng {R} notation. Note: To download the simulation files provided in this article, the reader must have LTSpice installed. this is how I roll it in 1 run (same method as what mr stilltrying said). 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. For additional information you may view the cookie details. Subject of the new topic: (c) and (d) answer -> RL = 12 for P = 33.33 W. To answer (a), we need the open circuit voltage (Voc) and the Thevenin resistance (Rth). I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. Are you sure you wish to repost this message? Stepping Parameters in LTspice IV - YouTube LTSpice: Step multiple parameters simultanious - Electronics Forums LTSpice problem with varying parameters | All About Circuits Can I have two (or more) different symbols for the same LTspice schematic? Run the simulation and you should get the same results as in Figure 3. LTspice - Resistor value controlled by on/off switch, How can one label a node with more than one name in SPICE/ LTspice. Note: * is used as a comment in SPICE. Open the edit screen of resistance R2 by "right clicking" the resistance R2 of the schematic with the mouse. 2023 One parameter sweep/step can control multiple component values through expressions. It is performed simultaneously with transient analysis, AC analysis, DC sweep analysis, etc. LTspice can be downloaded for free from here. Now LT spice knows what you're talking about when you start writing your scripts. Therefore, for: .step param A list 1 2. The addition of the curly braces around the variable is important as it tells LTspice IV that X is a parameter. I've done the trick with the Component Attributes dialogue on both components already. 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. Subject of the new topic: 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. How to Sweep Temperature in LTSpice with Step by Step Tutorials Check that SINE is selected and DC offset [V]: 0, Amplitude [V]: 2, Freq [Hz]: 500 is input. In this article, we only used the waveform viewer to check the voltage waveforms of V(OUTPUT) with the voltage probe. 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. 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. 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. You can break that back out into A and B as it executes. LTSpice cursors on different runs of same parameter It would take time to add and adjust values using the .step list method. Trying to understand how to get this basic Fourier Series. The probe cursor indicates which 'key' (i.e. 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. The Group moderators are responsible for maintaining their community and can address these issues. 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. What is \newluafunction? You need to replace this with your parameter designator; put that inside {} brackets, e.g. For LTspice, use tables to define params. 1. The waveform viewer is a function that displays the simulation results executed with LTspice as a LTspice-Independent Voltage Source Setting. To learn more, see our tips on writing great answers. Remember that R5 relates to the parameter designator. 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. Yes I realized that immediately after sending. Linear regulator thermal information missing in datasheet. Use MathJax to format equations. 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 ltspice step multiple parameters For this exercise, we have 2 variable parameters, Vs and R, which gives a total of 4 possible solutions. To be clear I've used {R5} for my convenience and understanding.