I managed to do it using the TABLE function for each of the five variables. It could be {Pickle1} and it would still work. 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. Found the answer in the group. 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: 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? LTspice Tutorial: Part 5 - Simon Bramble 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. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. The addition of the curly braces around the variable is important as it tells LTspice IV that X is a parameter. Import Parametric Sweep data from LTSPice into Matlab, Modelling a low-pass filter on LTSpice to filter an input square wave at 50kHz to obtain a sinusoidal output at 50Hz, LTSpice, AD8677 instance has more connection terminals than the definition, LTspice singular matrix error by changing model parameters. 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. Notice Uin could be used as {Uin} in a voltage source or similar and so on. 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). 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. In this case, the resistance value is varied from 1k to 10k. It only takes a minute to sign up. PSPICE is more suited for this but if you are good at scripting, this should be possible to solve in NGSPICE. 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. I am not sure if my question was well understood (yes I did find other similar posts but no applicable answers). A .param statement can also be placed on a schematic as a SPICE Directive. spice parameter sweep | All About Circuits This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. Figure 1. I'm confused, do you want to simulate 3 situations or more? is no. Are you sure you wish to delete this message from the message archives of LTspice@groups.io? The LTSPICE function u(x) is a step function with u(x)=1 for x > 0 and u(x)=0 else. The specialty shows in the expression 1-u(Temp) in the last line. How can I use it? After simulation, when you move the cursor close to the schematic wiring, the cursor changes to voltage probe. Would the magnetic fields of double-planets clash? 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: . Of course, if you know the syntax format, you can also enter it on the "Edit Text on the Schematic" screen. Linear regulator thermal information missing in datasheet. First, prepare a schematic for parametric analysis with LTspice. Use MathJax to format equations. Lets find the value of RL that corresponds to the the maximum power transfer to RL in the circuit from Figure 4. However, it can be set by R = <expression>, and the resistance value can be changed by specifying the node voltage in <expression>. Make sure the "SPICE directive" is selected and enter ".step". 2023 Would the magnetic fields of double-planets clash? He holds a Master of Science degree in electrical and computer engineering from University of California, Santa Barbara. The only change that we need to make is to add a set of values for the variable parameter RL. Difficulties with estimation of epsilon-delta limit proof, Follow Up: struct sockaddr storage initialization by network format-string. For more information on how to use the .step command to improve your understanding of a schematic, review the Help Topics in LTspice IV. They are defined with the .op SPICE directive " .param <name> = <value> ". communities including Stack Overflow, the largest, most trusted online community for developers learn, share their knowledge, and build their careers. 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. Basic Circuit Simulation with LTspice - Technical Articles The .step command is then used to step R through different values. 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. 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. I'm trying to get the results of simulation in "DC operating point" mode with a few varied (.STEP) parameters (example b. Visitors have the right to withdraw their consent. 1. We are commenting the second Spice directive for now. Then use that parameter's values to control the other. How do/should administrators estimate the cost of producing an online introductory mathematics class? At LTspice, are there any methods to change the values at once? 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. Note: * is used as a comment in SPICE. LTspice parametric sweep: how to force the simulator to continue with the next step? Are you sure you wish to repost this message? 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. Now lets say that we want to analyze Vo for 10 different types of RL. You should now see .tran 10m at the bottom of the screen. Thanks for weighing in! Any number of parameters can be made into variables, however LTspice will run simulations on all the different combinations of each value. However, with the .step increase order method that can be done faster. Read more about our privacy policy. This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. Subject of the new topic: I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. Analog Devices is in the process of updating our website. LTspice: Stepping Parameters | Analog Devices ltspice - How to use .step param with more than two parameters in This video provides an overview of how to use the .STEP command to perform repeated analysis of a circuit in LTspice. 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. (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). 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. Here is a list of some hotkeys for creating your schematic: R: Place resistor. .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) 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 general idea (not the implementation) came from the LTspice yahoo group (e.g. Its quite a . 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. LTspice - Resistor value controlled by on/off switch, How can one label a node with more than one name in SPICE/ LTspice. To implement this in LTspice, perform the following steps: Figure 1. color of data point should only depend on one parameter, not the other.). Thankfully, LTSpice generates data when doing a transient analysis with multiple stepping parameters fairly easily. Subscribe today! What LTSpice does is automatically set each step to have a certain color automatically. One parameter sweep/step can control multiple component values through expressions. Click Run on the toolbar to run the simulation. LTspice is a powerful and widely used SPICE simulation application. 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. The waveform viewer is a function that displays the simulation results executed with LTspice as a LTspice-Independent Voltage Source Setting. How? Thank you. and what would happen then? Another way to simulate a set of values at the same time is to use the increasing order option of the .step command. 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. Now LT spice knows what you're talking about when you start writing your scripts. In this post (. To learn more, see our tips on writing great answers. I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. In this article, we will focus on how to set up a independent voltage source for analysis. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. rev2023.3.3.43278. PDF Creating Subcircuits and Hierarchical Blocks in LTspice Using Kolmogorov complexity to measure difficulty of problems? 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. 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 . LTspice can be downloaded for free from here. The .param directive allows the creation of user-defined variables. 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 Group moderators are responsible for maintaining their community and can address these issues. I think this message isn't appropriate for our group. Can be one line. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Connect and share knowledge within a single location that is structured and easy to search. communities including Stack Overflow, the largest, most trusted online community for developers learn, share their knowledge, and build their careers. ltspice step multiple parameters. Perform parametric analysis using the schematic in the following article. Is it possible to step 2 parameters together? Why is this sentence from The Great Gatsby grammatical? Firstly, The parameter you wish to vary needs to be designated. You can break that back out into A and B as it executes. Lets build the LTSpice circuit with the original RL value first. We have already set the signal source in the article of "How to Draw a Schematic", but let's check it just in case. Lets build the circuit in LTSpice. This time, we set up transient analysis to be performed simultaneously with parametric analysis. Press question mark to learn the rest of the keyboard shortcuts. This is not what OP is asking about. You can break that back out into A and B as it executes. During homework exercises or labs, sometimes you need to analyze the circuits for different components values. For How to set up detailed transient analysis. LTspice: How can I show multiple probes with waveforms using stepping parameters in different colors? Thanks Andy. 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. One way to achieve this is to create a list of desired values to test. Example: .step oct v1 1 20 5. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? More than three nested parametric sweeps in LTspice What is \newluafunction? Unfortunately, there's no editing messages but I knew whoever responded would be sure to correct me : ). Now I want to take that parameter and apply it to my components. Are you sure you wish to repost this message? Press keyboard letter "T" to show the spice directive. LTspice IV: Using the .STEP Command to Perform Repeated Analysis. 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. I could open up the plot legend that shows the color of each point, but I don't see anywhere to change these settings. "You can make nested .step loops up to 3 levels. Another use of variable parameters can be to find the maximum power transferred to a load. Nested simulation loop in LTSpice | diyAudio Managing temperature in LTSPICE | Electronics Forums The DC operating point, .op simulation doesnt output an answer with respect to time. {R5} then Save. Well for one the table command wants an index, which is X, then a set of xy pairs. rev2023.3.3.43278. I have tried setting X to 0 1 2 instead of 1 2 3, but that does not work either. How to pass a multiple value parameter with single quote to stored I think this violates the Terms of Service. Making statements based on opinion; back them up with references or personal experience. 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 Visit Stack Exchange Tour Start here for quick overview the site Help Center Detailed answers. You can set custom plot colors in the preferences.