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} 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. 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. 1. Are you sure you wish to repost this message? 3: R1 = 1 k\$\Omega\$, R2 = 1 M\$\Omega\$. Would the magnetic fields of double-planets clash? Thankfully, LTSpice generates data when doing a transient analysis with multiple stepping parameters fairly easily. From the list of options select the desired one. 2023 So I wrote a C++ script to create the tables as (long) text files. Instead a combination of parameters using SPICE directives needs to be called for help . By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. The addition of the curly braces around the variable is important as it tells LTspice IV that X is a parameter. Run the simulation and you should get the same results as in Figure 3. However, to my knowledge it is not possible to achieve what you asked for. https://groups.io/g/LTspice/topic/50201465#60860). LTspice: How can I show multiple probes with waveforms using stepping parameters in different colors? The result would be three simulation runs with C1 matching each of the values specified in the ".step" statement for each run. How should I go about getting parts for this bike? Visitors have the right to withdraw their consent. You can break that back out into A and B as it executes. The general idea (not the implementation) came from the LTspice yahoo group (e.g. It described a complete circuit, so I extracted just the SCR description. The specialty shows in the expression 1-u(Temp) in the last line. 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). They are defined with the .op SPICE directive " .param <name> = <value> ". Interested in the latest news and articles about ADI products, design tools, training and events? What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? parameterized capacitance in the R-C circuit I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. It only takes a minute to sign up. 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. 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. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? So the table of the values start with the index identifier (here n) then follows the pairs index, value . Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Groups.io. PSPICE is more suited for this but if you are good at scripting, this should be possible to solve in NGSPICE. For more information on how to use the .step command to improve your understanding of a schematic, review the Help Topics in LTspice IV. Unfortunately, there's no editing messages but I knew whoever responded would be sure to correct me : ). posted on January 25, 2022. In LTSpice the table command really creates a kind of dictionary where you have to specify key value pairs. Thanks Andy. Yes I realized that immediately after sending. If you preorder a special airline meal (e.g. The proper directive for your case would then be: and set the value of the resistors to {R1} and {R2} respectively. communities including Stack Overflow, the largest, most trusted online community for developers learn, share their knowledge, and build their careers. The .step command causes an analysis to be repeatedly performed while stepping through a model parameter, global parameter or independent source. Connect and share knowledge within a single location that is structured and easy to search. For How to set up detailed transient analysis. Visit Stack Exchange Tour Start here for quick overview the site Help Center Detailed answers. I cannot use Monte Carlo since the cursor information is missing (i.e. During homework exercises or labs, sometimes you need to analyze the circuits for different components values. Does a summoned creature play immediately after being summoned by a ready action? 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). This video provides an overview of how to use the .STEP command to perform repeated analysis of a circuit in LTspice. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? This is the setting for performing a parametric analysis that changes the variable R2 from 100 to 400 ohms in 100 ohm linear steps. One parameter sweep/step can control multiple component values through expressions. "You can make nested .step loops up to 3 levels. Found the answer in the group. Therefore, for: .step param A list 1 2. Linear Algebra - Linear transformation question. Would the magnetic fields of double-planets clash? How can I use it? The ".step" of dot command appears, so place it at an appropriate position. Model Statements: Some devices, such as, transistors and diodes require information on the device in order to make calculations. I think this violates the Terms of Service. 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. Are you sure you wish to delete this message from the message archives of LTspice@groups.io? The PARAM R can be referenced in a component value usng {R} notation. 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. If you want to lay out the schematic editor and graph pane, see the following . How do/should administrators estimate the cost of producing an online introductory mathematics class? I had the sense that LTSpice does not support this, but I wanted to bounce this off of some other people first. What is the point of Thrower's Bandolier? But this wouldn't vary the parameters independently. 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. 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. In this case, the resistance value is varied from 1k to 10k. .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) I think this message isn't appropriate for our group. To learn more, see our tips on writing great answers. Press question mark to learn the rest of the keyboard shortcuts. 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. into the resistor value field. LTspice can use auxiliary units other than m as shown in the following table. This time I set the variable to R2, but anything with alphanumeric characters is fine. Lets start by creating a user-defined variable in LTSpice. 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. Open the edit screen of resistance R2 by "right clicking" the resistance R2 of the schematic with the mouse. To learn more, see our tips on writing great answers. Now I want to take that parameter and apply it to my components. http://tech.groups.yahoo.com/group/LTspice/files/%20Tut/Stepping%20to%20the%20max/. The only change that we need to make is to add a set of values for the variable parameter RL. 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). I hope I'm being clear. 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. How? What LTSpice does is automatically set each step to have a certain color automatically. The problem was that the size of the tables (given by the number of total parameter combinations) was prohibitive to write by hand. 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. Note: For this approach to run without errors, make sure that the size of the list is equal to number of variable parameters. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? 2. However, with the .step increase order method that can be done faster. Can be one line. 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. The command .step performs parameters sweeps. 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 The command ".step" performs parameters sweeps. Lets find the value of RL that corresponds to the the maximum power transfer to RL in the circuit from Figure 4. Refer to the following article for the detailed setting method of transient 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}. We comment the first SPICE directive line and uncomment the second line. How to use Slater Type Orbitals as a basis functions in matrix method correctly? Welcome to EE.SE! I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. I think this message isn't appropriate for our group. By computing 1-u(Temp) the temperature coefficient tc3 is effective only if Temp < 0 C. After running the simulation we get the following plot with Vo vs RL. 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? To implement this in LTspice, perform the following steps: Figure 1. I think this violates the Terms of Service. Click on "Simulate" icon bar then "Edit Simulation Cmd" to show the Transient section. Interested in the latest news and articles about ADI products, design tools, training and events? Thankfully, LTSpice generates data when doing a transient analysis with multiple stepping parameters fairly easily. Subscribe today! You should now see .tran 10m at the bottom of the screen. Groups.io, Is there a way to have LTspice step multiple parameters as a, --- In LTspice@, "dan.friedrichs" . How to pass parameters to subcircuits in LTSpice with the include statement? It is provided free of charge by Analog Devices (originally by Linear Technology).