I've searched for the particular LDMOS FET (mrfx1k80h) that I was hoping was already modeled, but without success. So now, I was hoping I could find out how to model the component given the data in its data sheet. Is there a recommended tutorial or such that would get me started? Cheers Luke

Hello LT Team I want to save waveforms of different simulation runs on the same panel/pane. Is there a way to do that apart from .step directive? Thanks, Raymond K.

Take a look at this book and website. Cool stuff.

Hello, I am trying to better understand the basic diode modelling in LTSpice and I am having difficulties in determining the source of some differences between computed values and simulation values. I have uploaded the diode_model_error.asc file to the Temp folder. It contains a basic simulation using the LTSPICE model for the 1N4148 diode. The first discrepancy is the slightly different value computed for Ut. The simulation indicates in the log file the following values: k_: k=1.38065e-23 q_: q=1.60218e-19 t_: t=300.15 ut_: ut=0.0258641 Nevertheless, if I separately compute the Ut (in mathcad, for example), I do get a slightly different value, namely: 0.0258649 What is the source of this error? Apart from that, I use the following formula to compute the expected voltage drop over the diode at a given current: Vf = RS * ID+N * Ut * ln((ID/IS)+1) where RS, N and IS are the diode model parameters If I manually compute Vf for ID=20mA using the ut=0.0258641 value, I obtain Vf = 731.2553707mV If I manually compute Vf for ID=20mA using the ut=0.0258649 value, I obtain Vf = 731.2776377mV In both cases, these values are slightly different from the value I see in the simulation: if I add the current through the diode to the plot, I see a voltage of 731.285mV on the horizontal axis corresponding to a current of 20mA. What is the cause of this difference? It is not big, but I would like to get to the bottom of it, if possible. Best regards, Cristian

I want to replace some Pspice syntax for UGATE and UEFF with LTspice in a file I downloaded. Can some one confirm the correct replacements in: .MODEL U_SN7404_1 UGATE(TPLHTY=22N TPHLTY=15N) and .MODEL U_SN7476_1 UEFF(TPCLKQLHTY=35N TPCLKQHLTY=35N) Tnx, Tim

Hello All, Does anyone have a spice model for the MPSH69/MMBTH69LT1 PNP? Thanks!

Hello All, Tony Casey wrote: Is your aim to actually run in batch mode from the command line? If so, you might experiment whether output re-direction using the ">" of ">>" generates any kind of output. The operator might not be exactly the same, I'm more used to using a BASH command line. Yes, LTspice in command line -b batch mode, called from a DOS batch file, using FOR to cycle through lets say for this example one hundred files named Batch_xxx.asc that contain the following type data customized for each run. The project, which does not change from run to run, is .included in each Batch_xxx.asc file as a .net file. .option noopiter GminSteps=0 pTranMax=1u .options trtol=7 gshunt=1.8e-8 cshunt=1e-15 .options PlotWinSize=0 NoMarch .TEMP 60 .tran 0 108m 48m startup .param OCTrip=942m .param OCRpt=912m .param Right=0 .param ic0=0 .param ic1=0 .param ic15=0 .param Vsup=24 .param Wire=2 .param Buss=10 .param ILoad=4 .param Test=0 .param ISon=if(Test>0.7, 1, 0) .param SwSon=if(Test<0.3, 1, 0) .param SwRDon=if(Test<0.3 & Right>0.5, 1, 0) .inc CS_Breaker_Batch.net .inc CS_Breaker_Batch.meas As you suggested, I tried output redirection on the -b command line. It produces a blank file. If nothing does what you want, you could do worse than make a feature request. I can't. In LTspice, I click "Help-Get Support on EngineerZone" which opens "https://ez.analog.com/design-tools-and-calculators/ltspice/" in my browser Firefox. It also fails in Chrome but somewhat differently. When I click the "Ask a Question" button, the page goes blank and I see ez.analog.com followed by id.analog.com followed by ez.analog.com followed by id.analog.com for several minutes followed by some random page like: Energy Monitoring and Metering Q&A How to Calculate the power factor in ADE7763 Which still leaves me no way to ask a question or make a feature request. If I instead click "Log In" on the "https://ez.analog.com/design-tools-and-calculators/ltspice/" page I get: That Was Unexpected We apologize, but an unexpected issue prevented the page you requested from being available. We've logged the issue so the site administrator can resolve the problem. I try "Log In" quite often so I've seen that message many times but no site administrator has ever resolved the problem. I tried "Log In" on "https://ez.analog.com" from my another workstation which does bring up a login page. After logging in, the page blips and flips and blips until returning to "https://ez.analog.com" with no indication that I have been logged in. Clicking "Ask a Question" on that workstation did the same ez, id, ez, id dance to finally dump me into: High-Speed DACs Q&A Do I need calibration circuit for AD9744 to produce high-precision output? So, at this point, I will return to relearning Excel macro language. I wrote Excel macro for a living some 15 years ago, so now I'm going to brush off some of my old macro work to see if I can relearn enough basic for applications to fully automate this -b batch process. Thank you Tony. All for now Sent: Saturday, June 01, 2024 at 12:54 PM From: "Tony Casey via groups.io" <tony=ritecom.com@groups.io> To: LTspice@groups.io Subject: Re: [LTspice] Batch Issues

Hello All, Andy wrote on 6/10/24 in the thread "Spurious 'pin mismatch' error": "There is a "special case" of LTspice symbols, which happens when both the SpiceModel and ModelFile attributes are defined in the symbol. In that case, and only that case, the SpiceModel attribute turns into a drop-down menu from which you can select (from the drop-down list) the specific subcircuit from the model file." I have wondered for years how that was done. I have run across components in the past with that drop down list feature but was unable to reverse engineer why that drop-down list happened. But my memory says that those components presented the drop-down list in a primary dialog upon right-clicking the component. Ctrl-Right-Click did not open, and could not open, the alternate "Component Attribute Editor" dialog in which the Open Symbol button appears. Memory tells me, those components opened a dialog similar to, but not exactly like, the dialog one gets by right-clicking a native transistor. That dialog immediately showed the drop-down component selection list as a clearly understandable drop-down list with a visible down arrow. I have the Littelfuse SMAJxxxCA.lib TVS diode library which contains all of Littelfuse's TVS diodes in the series. For whatever reason, the symbol was not constructed correctly and attached to only one of the many diodes in the library file. SpiceModel in my symbol was filled in with "TVS_Diode_SMAJxxxCA.lib" but ModelFile was blank. SpiceModel in the alternate "Component Attribute Editor" dialog, which in this case, opens with either Right-Click or Ctrl-Right-Click, was filled in with "SMAJ24CA". So I hit the "Open Symbol" button and added "SMAJ24CA" to the symbol's SpiceModel value so it was no longer blank. I saved the symbol and backed out all the way to the schematic. I then erased the SMAJ24CA component from the schematic and closed and reopened the schematic. I have noticed that LTspice has the nasty habit of remembering the attributes of a symbol beyond those change(s) and the only way to get the change(s) to stick is to erase and replace the component from the Place dialog. Closing and reopening the schematic was just for good measure while stumbling around in a cloud of uncertainty. I opened the schematic and placed the newly changed symbol on the schematic. Right-clicking the SMAJ24CA component displayed nothing different than before. I checked the symbol and yes, both SpiceModel and ModelFile were filled in correctly. I exited back to the Component Attribute Editor to analyze the ModelFile attribute. I double-clicked the Display checkmark to extinguish it, OK'ed out and right-clicked back in. The SMAJ24CA disappeared from the schematic and ultimately I made it reappear. Clicking the SpiceModel attribute highlighted it, enabling one to change it but, that was no different than before. In my old age, my clicker finger has become a bit shakey and solely by accident I double-clicked the SpiceModel attribute. Low and behold, the SpiceModel attribute changed to a selection box with a down arrow now visible. Clicking the down arrow dropped a list showing all the diodes in the TVS_Diode_SMAJxxxCA.lib file. So, for anyone trying to accomplish the same by filling in the SpiceModel and ModelFile attributes of a symbol. You must double-click the SpiceModel line of the Component Attribute Editor to get the drop-down list to appear. So now that I know how to accomplish the drop-down list feature I'm left with one remaining question. Can anyone tell me how to get that locked down feature of a component so that right-clicking a component on a schematic opens a dialog similar to right-clicking a native transistor and Ctrl-Right-Click cannot open the Component Attribute Editor which means that the symbol cannot be edited from the schematic? At the moment, I cannot find a component that acts like that but, I am sure that I have seen that kind of locked down behavior in the past. Thank You

Hello, I get this error, how can i correct it ? Thank you in advance. Best regards, Rudi

Sorry if I am repeating myself, old age. When running a stepped analysis to plot loop gain after each run the program insists on loading waveforms before the next run. Whilst it says "esc to abort" that does not seem to work. Is there a way to stop it doing this in the first place or getting esc to work?

I tried to look in the archives for triac models and a diac model (I think almost all diacs are the same), but I can't find anything. Please advise. I suppose I could model a diac with two 35 V Zener diodes with a normal diode in series, in anti-parallel, but a proper model would be better. -- Signature OOO - Own Opinions Only Best wishes John Woodgate, Rayleigh, Essex UK Keep trying Virus-free.www.avg.com

I have uploaded Speed controller.zip, which tells me that the diac in the.ASC has more pins than the model has. Of course, the real error is something different, but I can't find it. -- Signature OOO - Own Opinions Only Best wishes John Woodgate, Rayleigh, Essex UK Keep trying Virus-free.www.avg.com

Hello, I am working on a circuit simulation in LTSpice that uses a 5STP 38N4200 thyristor. I have searched extensively but have not been able to find a model that has specs similar to this device (particularly its ability to handle high voltages (4200V) and currents). I was wondering if anyone could point me in the right direction or has a file that I could read in to my Spice schematic. Thanks!

Hello All, I have positive and negative 2.5V references (TL431). The plot display shows these typical values for those references. Plot Top Scale 2.4794438V and 1.3224156mA Plot Mid Scale 2.4794424V and 1.3224142mA Plot Bot Scale 2.4794410V and 1.3224128mA Anything less than 100uV I don't care to see. I would be pleased to see a flat line trace with the values 2.4794V and 1.3224mA for top, mid and bottom scales. Is it possible to get 1000 times less precision without breaking the sim? I don't need precision down to the 100nV level as it is now. I lowered the default abstol=1e-12 to abstol=1e-6, vntol=1e-6 to vntol=1e-3 and chgtol=1e-14 to chgtol=1e-7. The scales shown above did not change. Allthough, reducing abstol from 1e-12 to 1e-6 had a major beneficial effect. With abstol=1e-12, I always got around a hundred DefCons and the sim time was 465 seconds. With abstol=1e-6, I get no DefCons and the sim time was reduced to 371 seconds. Woohoo. Reducing vntol as described, reduced the sim time to 369 seconds. A modest gain. Reducing chgtol as described, reduced the sim time even more to 358 seconds. A better gain. Although, none of these changes reduced the plot precision below that 100nV mark. FYI, I've also had these settings for quite a while; .options trtol=7 gshunt=1.8e-8 cshunt=1e-15 noopiter GminSteps=0 pTranMax=1u. The gshunt and cshunt settings have been needed for a long time now to reduce singular matrix and/or timestep failures. I'm not sure what the trtol setting actually does except for trtol=7 causes faster sims. The remaining .options stop the different steppings that always fail to find whatever it is that they are looking for. Does anyone have any suggestions? Thank You

Hello All, I took a copy of an original project and did; "C:\Win32\LTC\LTspice24\LTspice.exe -netlist Original.asc" in a dos window. I renamed the net listing to BatchOriginal.net so it does not get clobbered by running "Original.asc" again. I made sure that all .spice directives had been removed from the copy of the original before net listing it. I then created a new "Batch.asc" schematic and placed all .param .tran etc... onto the new "Batch.asc" schematic. I then added ".inc BatchOriginal.net" to the "Batch.asc" schematic. Then I planned to create many appropriately named copies of the "Batch.asc" schematic to do a multitude of batch runs on the "BatchOriginal.net" project all with differing .params to get a multitude of "Original.mout" files to go to Excel for analysis. Now for the issue. I have uploaded a working example that detailes the issue. Any subcircuit device that has pin numbers creates usable measurements. Any subcircuit device that has pin letters fails to creates usable measurements. Run the "Original.asc" file and all is well. All six measurements work correctly. Next, run the "Batch.asc" file which .includes the BatchOriginal.net file. Only the first three measurements work correctly. There is no need to run it in batch mode. Using the GUI will prove the point. The last three measurements fail. In the plot window as well as in the measurements found in the log, "Ctrl-L". The working measurements are all of components with pin numbers. The failing measurements are all of components with pin letters. Please help. Thank You

I'm studying developing a website that stores schematics, and I would like to know if there is already any software that imports the ltspice format and converts it to PNG or JPG, or even that imports Deck Spice and converts it to an image. -- Carlos Delfino

I am looking for a couple of models for some diodes that I am reverse engineering a circuit. Does anyone have models for the 1N3611 and 1N3604?

Hello, I want to connect a 74HC14 to a local net instead of a VCC power supply. How can i proceed ? Thank you for your help. Rudi

I received a notice in my email about an upcoming webinar from Analog Devices titled "LTspice® 24: Faster, Better, Easier Circuit Simulation". The date of the webinar will be the 19th of June, 2024. There is a video with exactly the same title, "LTspice® 24: Faster, Better, Easier Circuit Simulation", released a week ago on the 24th of May. My first thought was that the webinar would be the video. (Not surprising; some webinars are pre-recorded.) But no. The presenters are not the same, and the pre-recorded video is quite short at less than 2 minutes. Perhaps it was meant to be a "teaser" for the webinar. On the other hand -- the description for the webinar suggests that it is not about LTspice! Perhaps either the description or the title is wrong. Short video: https://www.analog.com/en/resources/media-center/videos/6353604211112.html Recorded May 24, 2024 Presenter: Christian Westpfahl, Field Application Engineer, Analog Devices Only 1 minute 35 seconds long Future webinar: (link to event.on24.com not shown here, in case it is region-specific) Wednesday, June 19, 2024 Presenter: Benjamin Voegeli, Senior Principal Engineer, LTspice Tool Development, Analog Devices Unknown length (probably about 1 hour) Description accompanying the video: LTspice is a powerful, fast and free SPICE simulator, schematic capture and waveform viewer with a vast and growing model library. Currently, these libraries contain over 30,000 models, including over 5000 ADI product models and example circuits. LTspice’s waveform viewer allows you to probe schematics to display simulation results. LTspice 24 is a major upgrade released this year, running simulations faster than earlier versions. One significant new feature found in LTspice 24 is the addition of a FRA device, which can be used to perform frequency response analysis on non-linear circuits. This is particularly helpful in improving the loop stability and regulation speed of switch-mode DC-DC converters. Description for the upcoming webinar: In this webinar, find solutions for battery wear & tear, unnecessary power consumption, and over heating found in battery-powered applications and how supervisors optimize each circuit. Attendees will Learn: Common applications and challenges for battery-powered applications Basic function, features and benefits of using supervisors How to optimize battery-operated solutions using supervisors As you can see, the description does not say anything about LTspice. We will see if someone corrects it. Andy

I have found out following detail regarding setting local and global temperatures, read LTspice code below. Main point is, that you cannot pass the temperature variable in a function to the subcircuit and as a value expression. Has anyone made a similiar experience or explanation for this detail? Here, the relevant code, simply copy into a simulation file. << ; Case 1: Direct usage of TEMP variable as parameter (e.g., voltage): => overwriting works. .subckt SUB1 A B V1 A B {TEMP} .backanno .ends ; Case 2: TEMP variable in function and usage of the function in a component parameter (e.g., voltage): => overwriting works. .subckt SUB2 A B .func f(x) {TEMP} V1 A B {f(1)} .backanno .ends ; Case 3: Usage of TEMP variable in VALUE expression of controlled source: => overwriting works. .subckt SUB3 A B E1 A B VALUE={TEMP} .backanno .ends ; Case 4: TEMP variable in function and usage of the function in VALUE expression of a controlled source: => overwriting DOES NOT work. .subckt SUB4 A B .func f(x) {TEMP} E1 A B VALUE={f(1)} .backanno .ends .op X1A S0 0 SUB1 X1B S1 0 SUB1 TEMP=50 ; ==> works X2 S2 0 SUB2 TEMP=50 ; ==> works X3 S3 0 SUB3 TEMP=50 ; ==> works X4 S4 0 SUB4 TEMP=50 ; ==> DOES NOT work >>