Now, it is set to perform transient analysis for 10msec. 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). Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. LTSpice doesn't know what your talking about until you do that bit. 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 subscribe to this RSS feed, copy and paste this URL into your RSS reader. Are you sure you wish to repost this message? 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. We are going to work on this exercise in a slightly different order than the one asked by the exercise. 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. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. 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. Subject of the new topic: 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. Well for one the table command wants an index, which is X, then a set of xy pairs. Now lets change the values of RL automatically and analyze the results. I need to do three transient simulations with different values of certain resistors (conveniently called R1 and R2) in each. LTspice - Resistor value controlled by on/off switch, How can one label a node with more than one name in SPICE/ LTspice. 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}. 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). https://groups.io/g/LTspice/topic/50201465#60860). For this exercise, we have 2 variable parameters, Vs and R, which gives a total of 4 possible solutions. How can I use it? parameterized capacitance in the R-C circuit Are you sure you wish to repost this message? You can break that back out into A and B as it executes. In this article, we only used the waveform viewer to check the voltage waveforms of V(OUTPUT) with the voltage probe. From the list of options select the desired one. 1: R1 = 1 k\$\Omega\$, R2 = 10 k\$\Omega\$, Sim. 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. Steps may be linear, logarithmic, or specified as a list of values. 2023 Is it suspicious or odd to stand by the gate of a GA airport watching the planes? Add a .step command via a SPICE directive that specifies the steps for the parameter by a linear, logarithmic or list of values. Welcome to EE.SE! What is the point of Thrower's Bandolier? For the types of analysis, please see the following article. ltspice step multiple parameters. LTspice-Parametric Analysis(.step) | Spiceman (I.e. For the Nozomi from Shinagawa to Osaka, say on a Saturday afternoon, would tickets/seats typically be available - or would you need to book? I'm confused, do you want to simulate 3 situations or more? 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). Simulation with multiple .step parameters #24 - github.com I'm just wondering if I can manually change the color settings of the data points. The Group moderators are responsible for maintaining their community and can address these issues. I managed to do it using the TABLE function for each of the five variables. LTspice: Stepping Parameters | Analog Devices The .step command in this case steps the parameter R through the values 10k, 20k and 30k. 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. Use MathJax to format equations. Therefore, for: .step param A list 1 2. 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. (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). You can set custom plot colors in the preferences. You can break that back out into A and B as it executes. 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. Visit Stack Exchange Tour Start here for quick overview the site Help Center Detailed answers. How to pass parameters to subcircuits in LTSpice with the include statement? Of course, it does not matter if you enter 0.01 instead of 10m without using auxiliary units. The only change that we need to make is to add a set of values for the variable parameter RL. Can I specify that it should only change color when stepping one of the parameters? Another use of variable parameters can be to find the maximum power transferred to a load. Thankfully, LTSpice generates data when doing a transient analysis with multiple stepping parameters fairly easily. Now LT spice knows what you're talking about when you start writing your scripts. Another way to simulate a set of values at the same time is to use the increasing order option of the .step command. Your answer is a simple tutorial on a basic LTspice concept. Why does it seem like I am losing IP addresses after subnetting with the subnet mask of 255.255.255.192/26? Model Statements: Some devices, such as, transistors and diodes require information on the device in order to make calculations. Google searching for SCR SPICE models, I found a SPICE file on EDN's website. Would the magnetic fields of double-planets clash? Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? Press J to jump to the feed. Of course, if you know the syntax format, you can also enter it on the "Edit Text on the Schematic" screen. Tips for Using LTspice for Power Circuit Design parameter combination) was used for each simulation. Click on "Simulate" icon bar then "Edit Simulation Cmd" to show the Transient section. Parametric analysis analyzes while changing parameters such as resistance, capacitor, inductor, and power supply of electronic circuit. Found the answer in the group. Read more about our privacy policy. In addition, since the schematic was prepared here, if you want to start analysis immediately, download it by clicking the link below. 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. Gabino Alonso is currently the director of strategic marketing for the Power by Linear Group. 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. Groups.io, Is there a way to have LTspice step multiple parameters as a, --- In LTspice@, "dan.friedrichs" . 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. The addition of the curly braces around the variable is important as it tells LTspice IV that X is a parameter. Stepping Parameters in LTspice IV - YouTube Setup the transient command as below. Then use that parameter's values to control the other. Yes I realized that immediately after sending. ltspice step multiple parameters - HSS Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. However, with the .step increase order method that can be done faster. Lets build the LTSpice circuit with the original RL value first. To be clear I've used {R5} for my convenience and understanding. communities including Stack Overflow, the largest, most trusted online community for developers learn, share their knowledge, and build their careers. It is performed simultaneously with transient analysis, AC analysis, DC sweep analysis, etc. We are commenting the second Spice directive for now. Interested in the latest news and articles about ADI products, design tools, training and events? After we finish updating our website, you will be able to set your cookie preferences. into the resistor value field. The .step command is then used to step R through different values. 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! parameters through use of the Component Attribute Editor. spice parameter sweep | All About Circuits .step param B list 3 4. Are you sure you wish to delete this message from the message archives of LTspice@groups.io? Quick LTSpice question: LTspice plot color settings when stepping In that case, the simulation takes too long, advancing more slowly every time, as it would never end. 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. 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. In this article, we will introduce the "Initial Settings" when installing the latest version of LTspice XVII. LTSpice: How to start the step of a voltage source at a different time in the transient simulation than t=0s? Note: For this approach to run without errors, make sure that the size of the list is equal to number of variable parameters. In this LTspice requires setting of the signal source when simulating. As .tran 10m of dot command appear, place it at an appropriate position. 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 Thanks for contributing an answer to Electrical Engineering Stack Exchange! Input Name of parameter to sweep: R2, Nature of sweep: Linear, Start value: 100, Stop value: 400, Increment: 100. 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: . Sim. Parametric analysis analyzes while changing parameters such as resistance, capacitor, inductor, and power supply of electronic circuit. This could be a case of you get what you pay for. Make sure that the parameter of R2 is {R2}. Does the LT Spice monte carlo simulation definitely output the max and min voltage for any number of simulation runs? PDF Creating Subcircuits and Hierarchical Blocks in LTspice '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'. run a simulation immediately. This time I set the variable to R2, but anything with alphanumeric characters is fine. One parameter sweep/step can control multiple component values through expressions. I think this message isn't appropriate for our group. The waveform viewer is a function that displays the simulation results executed with LTspice as a LTspice-Independent Voltage Source Setting. In this article, we will briefly introduce the types of analysis that can be performed with LTspice. 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. G: Place ground. Parametric analysis is performed simultaneously with transient analysis, AC analysis, DC sweep analysis and so on. Linear Algebra - Linear transformation question. Then you use .include and .step param and the TABLE function in LTspice to perform the sweeps. Linear regulator thermal information missing in datasheet. Thanks for contributing an answer to Electrical Engineering Stack Exchange! I think this violates the Terms of Service. The LTSPICE function u(x) is a step function with u(x)=1 for x > 0 and u(x)=0 else. Subscribe today! Here is a list of some hotkeys for creating your schematic: R: Place resistor. Try LTspice - Making a Variable Resistor | Macnica Cytech Pte Ltd So the table of the values start with the index identifier (here n) then follows the pairs index, value . For LTspice, use tables to define params. 2023 Dear Donghoon Park, Thank you for creating such a useful tool! Visitors have the right to withdraw their consent. For example, combine parameter A and parameter B into a new parameter, (A*100+B), and sweep that. Instead a combination of parameters using SPICE directives needs to be called for help . The .step command causes an analysis to be repeatedly performed while stepping through a model parameter, global parameter or independent source. This time, set the feedback resistor R2 of the op-amp. is no. 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. After placement, right-click ".step" of the mouse to open the ".step Statement Editor" screen. 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. Click Run on the toolbar to run the simulation. In LTSpice the table command really creates a kind of dictionary where you have to specify key value pairs. Prior to joining ADI, Gabino held various positions in marketing, engineering, operations, and education at Linear Technology, Texas Instruments, and California Polytechnic State University. Open the edit screen of resistance R2 by "right clicking" the resistance R2 of the schematic with the mouse. Would the magnetic fields of double-planets clash? I guess I'll just have to export the data and plot it elsewhere. . #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. LTspice parametric sweep: how to force the simulator to continue with the next step? 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. Run the simulation and you should get the same results as in Figure 3. It is necessary to set the part which changes the parameter in parametric analysis. AC Op-amp integrator with DC Gain Control in LTspice, How to handle a hobby that makes income in US. Use MathJax to format equations. 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.