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. If you just want to simulate the 3 scenarios I wouldn't bother doing it with spice. 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. Analog Devices is in the process of updating our website. In this post (. The .step command causes an analysis to be repeatedly performed while stepping through a model parameter, global parameter or independent source. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. I think this violates the Terms of Service. In LTspice parameters are variables that can be reused throughout the schematic. It is performed simultaneously with transient analysis, AC analysis, DC sweep analysis, etc. Click Run on the toolbar to run the simulation. At LTspice, are there any methods to change the values at once? run a simulation immediately. Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? The probe cursor indicates which 'key' (i.e. If you want to lay out the schematic editor and graph pane, see the following . 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. Make sure that the parameter of R2 is {R2}. 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. Now lets say that we want to analyze Vo for 10 different types of RL. In this article, we will briefly introduce the types of analysis that can be performed with LTspice. 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. 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. The simulation time varies depending on the size of the circuit. Lets start by creating a user-defined variable in LTSpice. Learn more about Stack Overflow the company, and our products. Lets build the LTSpice circuit with the original RL value first. Is there a way to have LTspice step multiple parameters as a combination? On the output graph, add the signals of interest to that graph (in this case Vo) and add a cursor. If you preorder a special airline meal (e.g. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? Select Transient and enter 10 m for Stop time. I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. LTSpice: How to start the step of a voltage source at a different time in the transient simulation than t=0s? 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. You can set custom plot colors in the preferences. For additional information you may view the cookie details. Another way to simulate a set of values at the same time is to use the increasing order option of the .step command. We are almost there. 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. Asking for help, clarification, or responding to other answers. Menu Please refer to the linked article for an explanation of After all, in order to learn how to use LTspice, it should be faster to use the practice form and to learn first than to read the instruction manual. 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 is employed for this experiment. The LTSPICE function u(x) is a step function with u(x)=1 for x > 0 and u(x)=0 else. 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. Making statements based on opinion; back them up with references or personal experience. He holds a Master of Science degree in electrical and computer engineering from University of California, Santa Barbara. C: Place capacitor. communities including Stack Overflow, the largest, most trusted online community for developers learn, share their knowledge, and build their careers. I have tried setting X to 0 1 2 instead of 1 2 3, but that does not work either. It is performed simultaneously with transient analysis, AC analysis, DC sweep analysis, etc. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? 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 Found the answer in the group. AC Op-amp integrator with DC Gain Control in LTspice, How to handle a hobby that makes income in US. For this exercise, we have 2 variable parameters, Vs and R, which gives a total of 4 possible solutions. 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. Are you sure you wish to delete this message from the message archives of LTspice@groups.io? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Now I want to take that parameter and apply it to my components. Its quite a . 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). 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. 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! Asking for help, clarification, or responding to other answers. We comment the first SPICE directive line and uncomment the second line. 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. 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 problem was that the size of the tables (given by the number of total parameter combinations) was prohibitive to write by hand. For example, combine parameter A and parameter B into a new parameter, (A*100+B), and sweep that. This could be a case of you get what you pay for. MathJax reference. Sim. You are missing a comma in the Vac table after the pair 3,200V. The .step command has different flavors. (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 break that back out into A and B as it executes. A place to ask questions, discuss topics and share projects related to Electrical Engineering. Subscribe today! 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. . To learn more, see our tips on writing great answers. I hope I'm being clear. The command ".step" performs parameters sweeps. The new topic will begin with this message. Visit Stack Exchange Tour Start here for quick overview the site Help Center Detailed answers. On spice directive window, enter the step command as below. Input Name of parameter to sweep: R2, Nature of sweep: Linear, Start value: 100, Stop value: 400, Increment: 100. Now you can start using the Spice Directive dialogue box (.op Icon top right) and enter your script. and what would happen then? This command causes an analysis to be repeatedly performed while stepping the temperature, a model parameter, a global parameter, or an independent source. Any SPICE directive with a * in front of it, will not run during simulation. MathJax reference. What sort of strategies would a medieval military use against a fantasy giant? 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. Can I specify that it should only change color when stepping one of the parameters? Lets build the circuit in LTSpice. As .tran 10m of dot command appear, place it at an appropriate position. Here is an example waveform response of an RC circuit, for which the capacitance is stepped through three values. color of data point should only depend on one parameter, not the other.). Read more about our privacy policy. Open the edit screen of resistance R2 by "right clicking" the resistance R2 of the schematic with the mouse. I would like to simulate those three situations and plot them together. "You can make nested .step loops up to 3 levels. Besides, the Monte Carlo will take too long and it may 'duplicate' some combinations. For the types of analysis, please see the following article. After simulation, the graph pane will appear at the top of the schematic with the default settings of LTspice. Figure 1. How to pass parameters to subcircuits in LTSpice with the include statement? What LTSpice does is automatically set each step to have a certain color automatically. After we finish updating our website, you will be able to set your cookie preferences. It only takes a minute to sign up. 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. I think this violates the Terms of Service. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? 2023 posted on January 25, 2022. (I'm using the .op command). So I wrote a C++ script to create the tables as (long) text files. It is necessary to set the part which changes the parameter in parametric analysis. Thanks for contributing an answer to Electrical Engineering Stack Exchange! The specialty shows in the expression 1-u(Temp) in the last line. Lets find the value of RL that corresponds to the the maximum power transfer to RL in the circuit from Figure 4. It would take time to add and adjust values using the .step list method. How can I use it? What is the point of Thrower's Bandolier? 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). of runs I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. But this wouldn't vary the parameters independently. {R5} then Save. 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. 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). I've called the parameter Rx: The 1st line defines the steps I want to take as detailed above. Each param should have 3 pairs in it, not three values. Perform parametric analysis using the schematic in the following article. I'm just wondering if I can manually change the color settings of the data points. #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. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? Notice Uin could be used as {Uin} in a voltage source or similar and so on. In this case, the resistance value is varied from 1k to 10k. It's important to have all .step commands in one text box. 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 time, we set up transient analysis to be performed simultaneously with parametric analysis. Lastly the .op command drives the operation. 1: R1 = 1 k\$\Omega\$, R2 = 10 k\$\Omega\$, Sim. LTspice: How can I show multiple probes with waveforms using stepping parameters in different colors? #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. PSPICE is more suited for this but if you are good at scripting, this should be possible to solve in NGSPICE. So the table of the values start with the index identifier (here n) then follows the pairs index, value . Thanks Andy. The Group moderators are responsible for maintaining their community and can address these issues. 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. Subject of the new topic: If you simulate multiple parameters at the same time, LTSpice will compute all possible combinations between those parameters. 1995 - 2023 Analog Devices, Inc. All Rights Reserved, LTspice: Using the .STEP Command to Perform Repeated Analysis. Relation between transaction data and transaction id. Linear regulator thermal information missing in datasheet. Using Kolmogorov complexity to measure difficulty of problems? LTspice parametric sweep: how to force the simulator to continue with the next step? Below is a step-by-step method for how I added one. You should now see .tran 10m at the bottom of the screen. Read more about our privacy policy. Something like this: Paul asked how to step two parameters at once. 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. Trying to understand how to get this basic Fourier Series. G: Place ground. Instead a combination of parameters using SPICE directives needs to be called for help . 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. Then, in the waveform viewer, you can have three plot panes each showing only the result for each step by specifying "@" for the displayed value. However, it can be set by R = <expression>, and the resistance value can be changed by specifying the node voltage in <expression>. I'm trying to get the results of simulation in "DC operating point" mode with a few varied (.STEP) parameters (example b. 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. 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}. Unfortunately, there's no editing messages but I knew whoever responded would be sure to correct me : ). 2: R1 = 1 M\$\Omega\$, R2 = 10 M\$\Omega\$, Sim. 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. High Side Current Sense Amplifier with Reference and Comparator. 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. In this article, we only used the waveform viewer to check the voltage waveforms of V(OUTPUT) with the voltage probe. 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). 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!