Asking for help, clarification, or responding to other answers. To see the results with respect to time, we need to change the simulation type to .tran, transient analysis. It is important to understand that if you place the ground reference in a different point you are going to get different results. Can I have two (or more) different symbols for the same LTspice schematic? communities including Stack Overflow, the largest, most trusted online community for developers learn, share their knowledge, and build their careers. Another way to simulate a set of values at the same time is to use the increasing order option of the .step command. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. If you move the keys up and down in your keyboard you will be able to change between all the different answers. This command causes an analysis to be repeatedly performed while stepping the temperature, a model parameter, a global parameter, or an independent source. However, with the .step increase order method that can be done faster. I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. Use MathJax to format equations. However, it can be set by R = <expression>, and the resistance value can be changed by specifying the node voltage in <expression>. How do/should administrators estimate the cost of producing an online introductory mathematics class? This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. Check that SINE is selected and DC offset [V]: 0, Amplitude [V]: 2, Freq [Hz]: 500 is input. Interested in the latest news and articles about ADI products, design tools, training and events? and what would happen then? For this particular example, the increasing order option goes from 1k to 10k in increment steps of 2k. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. The way to do this is with a single .STEP command. To learn more, see our tips on writing great answers. Making statements based on opinion; back them up with references or personal experience. MathJax reference. I managed to do it using the TABLE function for each of the five variables. After running the simulation, you can iterate through all the answers the same way as we did in Figure 6 and 7. Input Name of parameter to sweep: R2, Nature of sweep: Linear, Start value: 100, Stop value: 400, Increment: 100. Sim. Here is a list of some hotkeys for creating your schematic: R: Place resistor. Lets build the LTSpice circuit with the original RL value first. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. 1: R1 = 1 k\$\Omega\$, R2 = 10 k\$\Omega\$, Sim. 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. Difficulties with estimation of epsilon-delta limit proof, Follow Up: struct sockaddr storage initialization by network format-string. The .step command is then used to step R through different values. For LTspice, use tables to define params. I am not sure if my question was well understood (yes I did find other similar posts but no applicable answers). Create an account to follow your favorite communities and start taking part in conversations. For example, combine parameter A and parameter B into a new parameter, (A*100+B), and sweep that. I think this violates the Terms of Service. 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. 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. I had the sense that LTSpice does not support this, but I wanted to bounce this off of some other people first. So I wrote a C++ script to create the tables as (long) text files. In this article, we will explain in detail how to set the simulation command used for the following six types of analysis. I cannot use Monte Carlo since the cursor information is missing (i.e. This video provides an overview of how to use the .STEP command to perform repeated analysis of a circuit in LTspice. 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 For the types of analysis, please see the following article. Can be one line. (I'm using the .op command). We are going to find c) and d) first and then find the equivalent Thevenin a), and at last we will find the current in RL for b). Click SPICE Directive on the toolbar to display Edit Text on the Schematic screen. Below is a step-by-step method for how I added one. Press keyboard letter "T" to show the spice directive. Steps may be linear, logarithmic, or specified as a list of values. The .step command in this case steps the parameter R through the values 10k, 20k and 30k. When a temperature sweep is used, LTSpice automatically vary the properties of components with respect to desired temperatures. Make sure that the parameter of R2 is {R2}. Are you sure you wish to repost this message? 3: R1 = 1 k\$\Omega\$, R2 = 1 M\$\Omega\$. Example: .step oct v1 1 20 5. Use MathJax to format equations. Then use that parameter's values to control the other. 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. This time, set the feedback resistor R2 of the op-amp. 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. 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. A place to ask questions, discuss topics and share projects related to Electrical Engineering. 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. Read more about our privacy policy. The command ".step" performs parameters sweeps. Is there a single-word adjective for "having exceptionally strong moral principles"? 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. I'm just wondering if I can manually change the color settings of the data points. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? The proper directive for your case would then be: and set the value of the resistors to {R1} and {R2} respectively. L: Place inductor. For example, we can parameterize the capacitance C1 in this simulation with the following modifications to the schematic. In this LTspice requires setting of the signal source when simulating. Are you sure you wish to delete this message from the message archives of [email protected]? Press J to jump to the feed. 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. 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. 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. 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). Each param should have 3 pairs in it, not three values. I would like to simulate those three situations and plot them together. . It would take time to add and adjust values using the .step list method. To implement this in LTspice, perform the following steps: Figure 1. Visit Stack Exchange Tour Start here for quick overview the site Help Center Detailed answers. This is useful for associating a name with a value for the sake of clarity and parameterizing your circuits. If you simulate multiple parameters at the same time, LTSpice will compute all possible combinations between those parameters. G: Place ground. Why does LTspice XOR gate have more than two inputs? I'm trying to get the results of simulation in "DC operating point" mode with a few varied (.STEP) parameters (example b. Parametric analysis analyzes while changing parameters such as resistance, capacitor, inductor, and power supply of electronic circuit. The best answers are voted up and rise to the top, Not the answer you're looking for? As .tran 10m of dot command appear, place it at an appropriate position. A .param statement can also be placed on a schematic as a SPICE Directive. Here is an example waveform response of an RC circuit, for which the capacitance is stepped through three values. In this article, we will briefly introduce the types of analysis that can be performed with LTspice. How to use .step param with more than two parameters in LTSpiceIV, electronics.stackexchange.com/questions/20811/, How Intuit democratizes AI development across teams through reusability. Linear Algebra - Linear transformation question. Is there a trick I can use to overcome the 'up to three nested loops' limitation? The command .step performs parameters sweeps. How to use Slater Type Orbitals as a basis functions in matrix method correctly? I've done the trick with the Component Attributes dialogue on both components already. Refer to the following article for the detailed setting method of the signal source. Select Transient and enter 10 m for Stop time. Note: To download the simulation files provided in this article, the reader must have LTSpice installed. 1995 - 2023 Analog Devices, Inc. All Rights Reserved, LTspice: Using the .STEP Command to Perform Repeated Analysis. MathJax reference. On spice directive window, enter the step command as below. #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. #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. 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. Something like this: Paul asked how to step two parameters at once. Yes I realized that immediately after sending. 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. Run the simulation and you should get the same results as in Figure 3. I have an LCR circuit including voltage sources where I need to sweep more than three parameters (nested sweep) for a transient simulation. We are commenting the second Spice directive for now. The waveform viewer is a function that displays the simulation results executed with LTspice as a LTspice-Independent Voltage Source Setting. 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. Menu This time, we set up transient analysis to be performed simultaneously with parametric analysis. The Group moderators are responsible for maintaining their community and can address these issues. Thank you. 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. Parametric analysis is performed simultaneously with transient analysis, AC analysis, DC sweep analysis and so on. The LTSPICE function u(x) is a step function with u(x)=1 for x > 0 and u(x)=0 else. I've called the parameter Rx: The 1st line defines the steps I want to take as detailed above. Confirm that ".step" of the dot command is displayed as ".step param R2 100 400 100". Visit Stack Exchange Tour Start here for quick overview the site Help Center Detailed answers. 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. https://groups.io/g/LTspice/topic/50201465#60860). In that case, the simulation takes too long, advancing more slowly every time, as it would never end. Now, it is set to perform transient analysis for 10msec. On the output graph, add the signals of interest to that graph (in this case Vo) and add a cursor. You can break that back out into A and B as it executes. 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 I think this message isn't appropriate for our group. This could be a case of you get what you pay for. This is not what OP is asking about. The probe cursor indicates which 'key' (i.e. 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. Thankfully, LTSpice generates data when doing a transient analysis with multiple stepping parameters fairly easily. The way to do this is with a single .STEP command. Lets build the circuit in LTSpice. 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. The list examples detailed above is a different way of achieving the end result required, but it looks like some of the comments are because, as was the case with me, it was not understood that you can't use the component designators without doing the {} thing. For instance, the forward voltage of a diode will change over different temperatures, the VBE of transistors, the RDSon of MOSFET and so on. Especially @afiskon and Ralf B.!If you liked this video be sure to check out my other videos and you can also subscribe to be up to date with all the new ones!If you want to support the creation of more and better videos please consider checking out: https://www.patreon.com/feszelectronics "You can make nested .step loops up to 3 levels. After we finish updating our website, you will be able to set your cookie preferences. 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. LTspice can use auxiliary units other than m as shown in the following table. It could be {Pickle1} and it would still work. Connect and share knowledge within a single location that is structured and easy to search. To plot a specific answer, right click on the graph, go to View and select Select Steps. 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. 2. After simulation, the graph pane will appear at the top of the schematic with the default settings of LTspice. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? In addition, since the schematic was prepared here, if you want to start analysis immediately, download it by clicking the link below. 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. Besides, the Monte Carlo will take too long and it may 'duplicate' some combinations. Note: * is used as a comment in SPICE. 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). The .step command has different flavors. Read more about our privacy policy. Press question mark to learn the rest of the keyboard shortcuts. Groups.io. Why does it seem like I am losing IP addresses after subnetting with the subnet mask of 255.255.255.192/26? 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. To learn more, see our tips on writing great answers. Subscribe today! 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). One parameter sweep/step can control multiple component values through expressions. LTSpice: Step multiple parameters simultanious Uwe Bonnes Aug 1, 2006 Aug 1, 2006 #1 U Uwe Bonnes Guest Is it possible to define the step function so that it influences multiple parameters at once? Setup the transient command as below. Here we are simulating RL from 10 to 10k in steps of 100. - jonk Apr 16, 2020 at 4:28 The result would be three simulation runs with C1 matching each of the values specified in the ".step" statement for each run. The Group moderators are responsible for maintaining their community and can address these issues. It only takes a minute to sign up. After much thrashing around, I found there are two aspects to this problem that need to be explored. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Dot command can be created with Edit Text on the Schematic. 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. http://tech.groups.yahoo.com/group/LTspice/files/%20Tut/Stepping%20to%20the%20max/. The new topic will begin with this message. Thanks for contributing an answer to Electrical Engineering Stack Exchange! I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. The new topic will begin with this message. 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 . Does the LT Spice monte carlo simulation definitely output the max and min voltage for any number of simulation runs? The PARAM R can be referenced in a component value usng {R} notation. LTspice parametric sweep: how to force the simulator to continue with the next step? 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. 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. Parametric analysis analyzes while changing parameters such as resistance, capacitor, inductor, and power supply of electronic circuit. 1. 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. 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). Add a .step command via a SPICE directive that specifies the steps for the parameter by a linear, logarithmic or list of values. In this article, we would like to easily check the analysis results with the LTspice voltage probe. 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. I guess I'll just have to export the data and plot it elsewhere. After simulation, when you move the cursor close to the schematic wiring, the cursor changes to voltage probe. 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. flower arranging classes northern virginia. 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. In this post (. It is performed simultaneously with transient analysis, AC analysis, DC sweep analysis, etc. Connect and share knowledge within a single location that is structured and easy to search. 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. 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 One of those flavors is the ability to include a list of values for your variable name. Thanks Ian.M, i tried it but cant seem to get it to work. Now lets change the values of RL automatically and analyze the results. parameterized capacitance in the R-C circuit In this article, it was placed near source V1. This multiple value parameter might have values with single quote, such as: abc, efg's, sms dio, 'you's dfd. I hope I'm being clear. Disconnect between goals and daily tasksIs it me, or the industry? As regards your second question, X would be the different indexes that let me access the table's values. 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. 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). 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} color of data point should only depend on one parameter, not the other.). To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 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. .step param B list 3 4. After we finish updating our website, you will be able to set your cookie preferences. LTspice - Resistor value controlled by on/off switch, How can one label a node with more than one name in SPICE/ LTspice. parameters through use of the Component Attribute Editor. 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. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? 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: . In this article, we will introduce the "Initial Settings" when installing the latest version of LTspice XVII. Making statements based on opinion; back them up with references or personal experience. 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. 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. By computing 1-u(Temp) the temperature coefficient tc3 is effective only if Temp < 0 C. Learn more about Stack Overflow the company, and our products. High Side Current Sense Amplifier with Reference and Comparator. Why does LTspice XOR gate have more than two inputs? This is the setting for performing a parametric analysis that changes the variable R2 from 100 to 400 ohms in 100 ohm linear steps. Thanks for weighing in! Are you sure you wish to delete this message from the message archives of [email protected]? 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. Notice Uin could be used as {Uin} in a voltage source or similar and so on. It is necessary to set the part which changes the parameter in parametric analysis. http://ltwiki.org/?title=Undocumented_LTspice#Stepping_a_Model, Powered by SMFPacks Advanced Attachments Uploader Mod. Firstly, The parameter you wish to vary needs to be designated. 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. 2023 After running the simulation we get the following plot with Vo vs RL. Open the Independent Voltage Source screen by right-clicking the signal source V1 of the schematic with the mouse. 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. Visitors have the right to withdraw their consent. Any SPICE directive with a * in front of it, will not run during simulation. Click Simulate-Edit Simulation Cmd in the menu bar to open the Edit Simulation Command screen. You can break that back out into A and B as it executes. Asking for help, clarification, or responding to other answers. How should I go about getting parts for this bike? 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. Would the magnetic fields of double-planets clash? What LTSpice does is automatically set each step to have a certain color automatically. A .model statement tells LTspice what parameters to use for modeling semiconductors. (I.e. Your answer is a simple tutorial on a basic LTspice concept. Well for one the table command wants an index, which is X, then a set of xy pairs. Something like 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. Click Run on the toolbar to run the simulation. How to pass parameters to subcircuits in LTSpice with the include statement? Its quite a . Step a parameter run number, and from it generate the other parameter values required : Code: [Select] .step param run 1 3 1 ; middle no. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. communities including Stack Overflow, the largest, most trusted online community for developers learn, share their knowledge, and build their careers. For this exercise, we have 2 variable parameters, Vs and R, which gives a total of 4 possible solutions.