Figure 1. It would take time to add and adjust values using the .step list method. On spice directive window, enter the step command as below. 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 of runs 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. Visit Stack Exchange Tour Start here for quick overview the site Help Center Detailed answers. The .step command is then used to step R through different values. The way to do this is with a single .STEP command. I have an LCR circuit including voltage sources where I need to sweep more than three parameters (nested sweep) for a transient simulation. He holds a Master of Science degree in electrical and computer engineering from University of California, Santa Barbara. Your answer is a simple tutorial on a basic LTspice concept. Step a parameter run number, and from it generate the other parameter values required : Code: [Select] .step param run 1 3 1 ; middle no. 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 Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. After much thrashing around, I found there are two aspects to this problem that need to be explored. Something like this: Paul asked how to step two parameters at once. The DC operating point, .op simulation doesnt output an answer with respect to time. vegan) just to try it, does this inconvenience the caterers and staff? If you want to lay out the schematic editor and graph pane, see the following . and what would happen then? The best answers are voted up and rise to the top, Not the answer you're looking for? 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. Note: To download the simulation files provided in this article, the reader must have LTSpice installed. This could be a case of you get what you pay for. Remember that R5 relates to the parameter designator. This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. Are you sure you wish to delete this message from the message archives of LTspice@groups.io? For the types of analysis, please see the following article. 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. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? I would for example like to increase some capacitor and decrease the stimulus volrtage source simultaniously. parameterized capacitance in the R-C circuit LTspice - Resistor value controlled by on/off switch, How can one label a node with more than one name in SPICE/ LTspice. 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 additional information you may view the cookie details. 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. 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. To plot a specific answer, right click on the graph, go to View and select Select Steps. this is how I roll it in 1 run (same method as what mr stilltrying said). PSPICE is more suited for this but if you are good at scripting, this should be possible to solve in NGSPICE. 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. 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. The .step command causes an analysis to be repeatedly performed while stepping through a model parameter, global parameter or independent source. Thanks Andy. To be clear I've used {R5} for my convenience and understanding. 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. Select Transient and enter 10 m for Stop time. Gabino Alonso is currently the director of strategic marketing for the Power by Linear Group. Note: For this approach to run without errors, make sure that the size of the list is equal to number of variable parameters. Learn more about Stack Overflow the company, and our products. Lets find the value of RL that corresponds to the the maximum power transfer to RL in the circuit from Figure 4. which parameter combination corresponds with which waveform). The Group moderators are responsible for maintaining their community and can address these issues. 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}. Normally, LTspice sets the resistance element parameter to a constant such as R = 10. ltspice step multiple parameters. Any number of parameters can be made into variables, however LTspice will run simulations on all the different combinations of each value. Well for one the table command wants an index, which is X, then a set of xy pairs. Now, it is set to perform transient analysis for 10msec. 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). In this article, we only used the waveform viewer to check the voltage waveforms of V(OUTPUT) with the voltage probe. Found the answer in the group. What is the point of Thrower's Bandolier? Subject of the new topic: In this article, we will briefly introduce the types of analysis that can be performed with LTspice. For additional information you may view the cookie details. After we finish updating our website, you will be able to set your cookie preferences. 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. 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. Note: * is used as a comment in SPICE. The probe cursor indicates which 'key' (i.e. They are defined with the .op SPICE directive " .param <name> = <value> ". By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Each param should have 3 pairs in it, not three values. This time, set the feedback resistor R2 of the op-amp. This is not what OP is asking about. The result would be three simulation runs with C1 matching each of the values specified in the ".step" statement for each run. LTspice parametric sweep: how to force the simulator to continue with the next step? It is performed simultaneously with transient analysis, AC analysis, DC sweep analysis, etc. 1: R1 = 1 k\$\Omega\$, R2 = 10 k\$\Omega\$, Sim. Will Gnome 43 be included in the upgrades of 22.04 Jammy? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. rev2023.3.3.43278. 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. MathJax reference. For this exercise, we have 2 variable parameters, Vs and R, which gives a total of 4 possible solutions. I'm trying to get the results of simulation in "DC operating point" mode with a few varied (.STEP) parameters (example b. If I'd used {Pickle} then the line would read: The next two lines in the script above tell LTSpice that the parameters for R5 and R6 should follow the steps designated as Rx. I think this message isn't appropriate for our group. Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? Are you sure you wish to delete this message from the message archives of LTspice@groups.io? Here is a list of some hotkeys for creating your schematic: R: Place resistor. did phineas and ferb die in a car accident. Relation between transaction data and transaction id. Something like The LTSPICE function u(x) is a step function with u(x)=1 for x > 0 and u(x)=0 else. Of course, it does not matter if you enter 0.01 instead of 10m without using auxiliary units. Refer to the following article for the detailed setting method of transient analysis. communities including Stack Overflow, the largest, most trusted online community for developers learn, share their knowledge, and build their careers. You are missing a comma in the Vac table after the pair 3,200V. Groups.io, Is there a way to have LTspice step multiple parameters as a, --- In LTspice@, "dan.friedrichs" . The best answers are voted up and rise to the top, Not the answer you're looking for? LTspice can use auxiliary units other than m as shown in the following table. It is necessary to set the part which changes the parameter in parametric analysis. #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. Why does LTspice XOR gate have more than two inputs? "You can make nested .step loops up to 3 levels. parameter combination) was used for each simulation. In this article, we will explain in detail the parametric analysis(.step) method in LTspice. The only change that we need to make is to add a set of values for the variable parameter RL. In that case, the simulation takes too long, advancing more slowly every time, as it would never end. After running the simulation, you can iterate through all the answers the same way as we did in Figure 6 and 7. In this article, it was placed near source V1. I think this violates the Terms of Service. The general idea (not the implementation) came from the LTspice yahoo group (e.g. How can I use it? Are you sure you wish to repost this message? I hope I'm being clear. You can break that back out into A and B as it executes. How do/should administrators estimate the cost of producing an online introductory mathematics class? C: Place capacitor. Press question mark to learn the rest of the keyboard shortcuts. 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. 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 On the output graph, add the signals of interest to that graph (in this case Vo) and add a cursor. 2: R1 = 1 M\$\Omega\$, R2 = 10 M\$\Omega\$, Sim. 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'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 . 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. 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. After placement, right-click ".step" of the mouse to open the ".step Statement Editor" screen. To implement this in LTspice, perform the following steps: Figure 1. Is there a way to have LTspice step multiple parameters as a combination? This includes: harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing. Now you can start using the Spice Directive dialogue box (.op Icon top right) and enter your script. Would the magnetic fields of double-planets clash? The specialty shows in the expression 1-u(Temp) in the last line. I managed to do it using the TABLE function for each of the five variables. Visitors have the right to withdraw their consent. into the resistor value field. 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. You've likely already given it a value, eg 1k0. Now lets say that we want to analyze Vo for 10 different types of RL. Press J to jump to the feed. How should I go about getting parts for this bike? Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? Add a .step command via a SPICE directive that specifies the steps for the parameter by a linear, logarithmic or list of values. - jonk Apr 16, 2020 at 4:28 Parametric analysis is performed simultaneously with transient analysis, AC analysis, DC sweep analysis and so on. The .step command in this case steps the parameter R through the values 10k, 20k and 30k. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Does a summoned creature play immediately after being summoned by a ready action? Asking for help, clarification, or responding to other answers. After simulation, the graph pane will appear at the top of the schematic with the default settings of LTspice. So I wrote a C++ script to create the tables as (long) text files. Analog Devices is in the process of updating our website. 2. 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. Click "SPICE Directive" on the toolbar to display "Edit Text on the Schematic" screen. I think this violates the Terms of Service. parameters through use of the Component Attribute Editor. Whats the grammar of "For those whose stories they are"? If you move the keys up and down in your keyboard you will be able to change between all the different answers. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. It described a complete circuit, so I extracted just the SCR description. 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} 3: R1 = 1 k\$\Omega\$, R2 = 1 M\$\Omega\$. 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. Thankfully, LTSpice generates data when doing a transient analysis with multiple stepping parameters fairly easily. Is it possible to step 2 parameters together? For more information on how to use the .step command to improve your understanding of a schematic, review the Help Topics in LTspice IV. Radial axis transformation in polar kernel density estimate. I'm just wondering if I can manually change the color settings of the data points. Input Name of parameter to sweep: R2, Nature of sweep: Linear, Start value: 100, Stop value: 400, Increment: 100. Visitors have the right to withdraw their consent. Learn more about Stack Overflow the company, and our products. It is performed simultaneously with transient analysis, AC analysis, DC sweep analysis, etc. 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. For this particular example, the increasing order option goes from 1k to 10k in increment steps of 2k. 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. Check that SINE is selected and DC offset [V]: 0, Amplitude [V]: 2, Freq [Hz]: 500 is input. In this post (. The new topic will begin with this message. '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'. 2023 The problem was that the size of the tables (given by the number of total parameter combinations) was prohibitive to write by hand. In LTspice parameters are variables that can be reused throughout the schematic. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? I've done the trick with the Component Attributes dialogue on both components already. I need to do three transient simulations with different values of certain resistors (conveniently called R1 and R2) in each. Click SPICE Directive on the toolbar to display Edit Text on the Schematic screen. Click Run on the toolbar to run the simulation. 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. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? 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. Instead a combination of parameters using SPICE directives needs to be called for help . 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 would like to simulate those three situations and plot them together. Firstly, The parameter you wish to vary needs to be designated. I could open up the plot legend that shows the color of each point, but I don't see anywhere to change these settings. We are commenting the second Spice directive for now. In this article, we will explain in detail how to set the simulation command used for the following six types of analysis. Linear regulator thermal information missing in datasheet. For this exercise, we have 2 variable parameters, Vs and R, which gives a total of 4 possible solutions. is no. . You need to replace this with your parameter designator; put that inside {} brackets, e.g. I cannot use Monte Carlo since the cursor information is missing (i.e. Why is this sentence from The Great Gatsby grammatical? After simulation, the graph pane will appear at the top of the schematic with the default settings of LTspice. This is the setting for performing a parametric analysis that changes the variable R2 from 100 to 400 ohms in 100 ohm linear steps. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 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. In this case, the resistance value is varied from 1k to 10k. The waveform viewer is a function that displays the simulation results executed with LTspice as a LTspice-Independent Voltage Source Setting. In this article, it was placed near source V1. color of data point should only depend on one parameter, not the other.). Google searching for SCR SPICE models, I found a SPICE file on EDN's website. If you have not drawn a schematic with LTspice, we recommend that you draw a schematic before analysis. http://tech.groups.yahoo.com/group/LTspice/files/%20Tut/Stepping%20to%20the%20max/. The addition of the curly braces around the variable is important as it tells LTspice IV that X is a parameter. 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. Run the simulation and you should get the same results as in Figure 3. The voltage waveforms of OUTPUT appear on the graph pane. What is \newluafunction? For example, combine parameter A and parameter B into a new parameter, (A*100+B), and sweep that. I had the sense that LTSpice does not support this, but I wanted to bounce this off of some other people first. It is important to understand that if you place the ground reference in a different point you are going to get different results. I have tried setting X to 0 1 2 instead of 1 2 3, but that does not work either. For LTspice, use tables to define params. The proper directive for your case would then be: and set the value of the resistors to {R1} and {R2} respectively. Make sure the "SPICE directive" is selected and enter ".step". The way to do this is with a single .STEP command. This video provides an overview of how to use the .STEP command to perform repeated analysis of a circuit in LTspice. To learn more, see our tips on writing great answers. How? Yes I realized that immediately after sending. Using Kolmogorov complexity to measure difficulty of problems? rev2023.3.3.43278. Why does it seem like I am losing IP addresses after subnetting with the subnet mask of 255.255.255.192/26? https://groups.io/g/LTspice/topic/50201465#60860). For example, combine parameter A and parameter B into a new parameter, (A*100+B), and sweep that. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? 1995 - 2023 Analog Devices, Inc. All Rights Reserved, LT6108 / LTC6994 Demo Circuit - Energy-Tripped Circuit Breaker with Automatic Delayed Retry (5-80V Input, 500mA Threshold), LTspice: AC Analysis Using The Step Command, LTspice: Using the .STEP Command to Perform Repeated Analysis. Welcome to EE.SE! Make sure that the parameter of R2 is {R2}. In LTSpice the table command really creates a kind of dictionary where you have to specify key value pairs. Thankfully, LTSpice generates data when doing a transient analysis with multiple stepping parameters fairly easily. In this article, we would like to easily check the analysis results with the LTspice voltage probe. L: Place inductor. 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). Of course, if you know the syntax format, you can also enter it on the "Edit Text on the Schematic" screen. 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. Perform parametric analysis using the schematic in the following article. You should see ".step param R2 100 400 100" at the bottom of the screen. Enter {R2} for the Resistance[]. Now lets change the values of RL automatically and analyze the results. If you ever get stuck working with LTSpice, there is a pretty comprehensive set of resources available in the Help menu, including more examples regarding usage. After running the simulation we get the following plot with Vo vs RL. The PARAM R can be referenced in a component value usng {R} notation. Notice Uin could be used as {Uin} in a voltage source or similar and so on. If you simulate multiple parameters at the same time, LTSpice will compute all possible combinations between those parameters. Can I specify that it should only change color when stepping one of the parameters? 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. LTspice is employed for this experiment. Sim. 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. How to use Slater Type Orbitals as a basis functions in matrix method correctly? Subscribe today! Parametric analysis analyzes while changing parameters such as resistance, capacitor, inductor, and power supply of electronic circuit. 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. Lastly the .op command drives the operation. Below is a step-by-step method for how I added one. This multiple value parameter might have values with single quote, such as: abc, efg's, sms dio, 'you's dfd. First, prepare a schematic for parametric analysis with LTspice. For instance, the forward voltage of a diode will change over different temperatures, the VBE of transistors, the RDSon of MOSFET and so on. LTspice table function. 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.