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MJ11021 Darlington NPN & PNP pair model help needed.

 

Hello,
New LTspice user.
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I am trying to build a model for MJ11021 to be used in an AB amplifier simulation.? Link to .
I made an attempt in building a model for the part PNP type first.? I also created a simulation to validate against the datasheet.
Validation part 1: DC simulation to Verify hFE and VCE.??
Never got past part 1!?
Part 2: Transient simulation? to measure switching time.
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I have uploaded the files to temp directory under /g/LTspice/files/Temp/MJ11021.zip
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It is not working and I am having a hard time figuring out how to fix the parameters in order to get it validated.? Any help and guidance in how to proceed to fix/tune the model parameters and how to setup the simulation to validate the model against key datasheet specs. would be greatly appreciated.
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Thank you in advance.
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Re: LTspice models do not work in Qspice

 

Hi Andy,
I will try to post more there to earn some trust I guess!
Regards,
Suded
Re: LTspice accuracy, used for calculations and measurements

 
Edited

On Tue, Apr 22, 2025 at 10:24 AM, Udo Huhn-Rohrbacher wrote:

To summarize: There was only a difference in version LTspice XVII(x64) 17.0.36.0 for different solver settings > Alternate vs. Normal

In my opinion, that is very odd that the solver would make a significant difference in the calculation of parameters x, y, and z.
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The fact that one of them printed a value of 3.14159?strongly suggests that this particular simulation forgot to set NUMDGT MEASDGT to greater than 6.? I think that's the only way the value would be limited to 6 digits.? I think the solver could not be the only difference.
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On a side note, it is slightly disappointing that LTspice seems to know pi to only 12 digits.? Perhaps it was programmed with only that many digits, making its remaining double-precision digits zeros.? Perhaps Mike Engelhardt found that more digits were truly unnecessary, in a circuit simulation program.
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All this is without verification on my part.? I am away from my work computer today, and I need to do some re-installations and fixing up, eventually.
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Thanks,
Andy
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Re: LTspice accuracy, used for calculations and measurements

 

After consulting 3 users regarding pi-measurements, we came to the conclusion

pi measurements resulted in ?3.14159265359 (11 digits after the decimal point) observed in the LT - versions

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user 1 : XVII(x64) 17.037.0;?? LTspice 24.1.6; solver: Alternate & Normal, no difference

user 2 :?LTspice 24.0.8 solver: Normal

user3: LTspice XVII(x64) 17.0.36.0 solver Alternate;

user3:?LTspice XVII(x64) 17.0.36.0 solver: Normal: pi = 3.14159

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To summarize: There was only a difference in version LTspice XVII(x64) 17.0.36.0 for different solver settings > Alternate vs. Normal

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We are satisfied with all your clarifications.

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Thank you very much

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Regards

Udo

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Re: Non-converging oscillation problem of inverse Jiles-Atherton model in LTspice

 

On Tue, Apr 22, 2025 at 08:03 AM, §¡§Ý§Ö§Ü§ã§Ñ§ß§Õ§â §¢§à§â§Õ§à§Õ§í§ß§à§Ó wrote:
I found that LTspice does not want to read the voltage in the delta node correctly!
That looks like it might be a language translation problem.
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I can't see a reason why LTspice would be unable to correctly read the voltage on any node.? But maybe that node's voltage was created (driven) wrongly, such that its voltage is incorrect?? That is a different problem than inability to read that voltage.
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I saw small oscillations here and there on various node voltages in this simulation.? I did not study it so I don't know what is supposed to happen.? That is just an observation.? I wonder if different simulation settings (plotwinsize, *tol tolerances, solver, timestep control) might be needed here?
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Andy
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Re: CD14538B for ngspice Kicad

 

On Tue, Apr 22, 2025 at 02:47 AM, Gamma Kiwi Al wrote:
Those are the files I am having trouble getting to work.
I get a Warning: can't find the initialization file spinit.
It seems that it is an ngspice question.? LTspice does not have nor use that file, as far as I can tell.? I don't use ngspice, but I'm guessing it is something that ngspice (only) needs.
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Why didn't you ask this question in the ngspice forum?? That should be the place to start.? Did you ask there already?
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Andy
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Re: Non-converging oscillation problem of inverse Jiles-Atherton model in LTspice

 

Hi.
I found that LTspice does not want to read the voltage in the delta node correctly! The result is huge, unreal values of H and M.
Re: CD14538B for ngspice Kicad

 

Thanks Andy, sorry to post in the wrong forum.
Those are the files I am having trouble getting to work.
I get a Warning: can't find the initialization file spinit.
Thanks?
Al
Re: CD14538B for ngspice Kicad

 

On Tue, Apr 22, 2025 at 01:31 AM, Gamma Kiwi Al wrote:
I wondered if anyone has seen a spice library for the CD14538B that will work in Kicad (ngspice).
This group is not about ngspice.? To the extent that ngspice model requirements differ from LTspice, we can not help with those.
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Did you try looking at these?
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??? Files > z_groups.io > Lib > Digital CD4000 > CD14538B and CD4538B
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If they have LTspice-unique elements in them, I can't help you there.
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I would also consider the part number without the "B" suffix.? And perhaps without the "1" prefix.
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Andy
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CD14538B for ngspice Kicad

 

I wondered if anyone has seen a spice library for the CD14538B that will work in Kicad (ngspice). So far I haven't found one that works inside Kicad without spitting out errors.
Thanks
Al??
Re: LTspice models do not work in Qspice

 

On Sun, Apr 20, 2025 at 08:41 PM, suded emmanuel wrote:
I could not upload my simulation file to Qspice it says that I have to earn few badges to do that!
It is kind of a "bummer" that Qorvo's QSPICE forum is like that.? New, first-time members there can't attach/upload their files.? On the one hand it makes some sense to stop new forum members from spamming them, but IMHO it makes little sense for customer support where first-time posters are the ones likely to need help with their models and schematics.? One hopes their settings are liberal enough to quickly overcome that hurdle.
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I guess it is one of the problems of corporate-run support.
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Andy
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Re: Modeling a CPE in LTPSICE

 

On Mon, Apr 21, 2025 at 03:25 PM, Maile, Keith wrote:

This has been asked before and I am just looking for the schematic: Files > Temp > Constant_phase_element1.asc

All files in Temp are there temporarily.? Hence the directory name "Temp".
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That file is now found here:
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Files > z_yahoo > Examples > Educational
Files > z_yahoo > Examples > Educational > Constant_phase_element1.asc
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There are other files near it with similar filenames.
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Andy
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Modeling a CPE in LTPSICE

 

¿ªÔÆÌåÓý

This has been asked before and I am just looking for the schematic: Files > Temp > Constant_phase_element1.asc

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Here¡¯s the old request and answer, Helmut did a great job but I can¡¯t find the schematic.

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--- In LTspice@..., "Helmut Sennewald"
<helmutsennewald@...> wrote:


--- In LTspice@..., "ks_bilder" <transients@> wrote:


Hello,

just started using LTspice and I don't know how to do the
following: In electrochemistry it is common practice to use
a so called constant phase element (CPE) in impedance analysis
of electrodes. The CPE is defined as follows:

Z = 1/( C * (j*w)^alpha )

where Z is the impedance, C equivalent capacitance, j imaginary
unit, w=2*pi*freq and 0 < alpha <= 1. For alpha=1 the CPE is
identical to an ideal capacitor.

What is the best way to define such an element in LTspice?
I would like to use the element in AC as well as in time
dependent modeling.

any help is appreciated!

Klaus


Hello Klaus,

Do you have some literature how other people have simulated it?

I think only a Laplace function can do the job.

There is absolutely no problem with any Laplace function in the
frequency domain simulation in (LT-)SPICE (.AC simulation).

The transient simulation (.TRAN) can make a lot of trouble with
these functions. The most important rule for transient simulation
is at least with LTspice that the value of a Laplace function
should fall to zero for high frequencies.
This means function with 1/s, 1/s**2 are good functions.

Now to some examples.

The value of the parameter alpha can be defined with a "param"-
statement. The character for exponent is ** and not ^ in LTspice.

.param alpha=1


CPE with G-source: OK in .AC but bad in .TRAN

Laplace=1e-6*s**{alpha}


CPE with E-source: OK in .AC, useful in .TRAN
The E-source circuit requires an additional current meter.
It's also necessary to add a small real value of 1u(1e-6)
to get useful results.

LAPLACE {I(V2)} = {1/(s**{alpha}*1e-6+1u)}


I have uploaded a test circuit to the Files section.

Files > Temp > Constant_phase_element1.asc


Best regards,
Helmut

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Re: Non-converging oscillation problem of inverse Jiles-Atherton model in LTspice

 

Thank you very much for your suggestion ¡ª you solved a problem that had troubled me for weeks. The convergence is indeed much better now. However, there are still some aspects of the model that puzzle me.

When my input B is a 50?Hz sine wave, the simulation only converges when the delay "tau" is set to 300?ns. If I reduce tau to 200?ns or smaller, the simulation still gets stuck at some point. Moreover, when I try to increase the frequency of B, tau = 300?ns no longer works. This behavior seems to make the model not very robust across different conditions.

Do you have any insights into what might be causing this?

(The new one is here: /g/LTspice/files/Temp/invJAmodel_2.asc)

Again, thank you so much for taking the time to help!
Re: Non-converging oscillation problem of inverse Jiles-Atherton model in LTspice

 

Try to implement the delay not using LC, but using RC. I replaced the voltage sources with an equivalent in the form of a controlled current source and an Rpar and Cpar connected to it. TAU=Rpar*Cpar~50nsec. ?But this is the case if the received voltage is not applied anywhere, but is used only in mathematical terms.
Re: Non-converging oscillation problem of inverse Jiles-Atherton model in LTspice

 

Thanks for your efforts! I¡¯ve seen the JA model you shared earlier¡ªit¡¯s excellent!

However, the circuit I¡¯m working on is the "inverse JA model", where B is the input and H is the output, unlike the usual forward case. I previously implemented the forward model (usual JA model) myself and it worked well without major convergence issues. But this time, the inverse version performs poorly in LTspice, and I¡¯m not sure why. Have you encountered similar convergence problems before?

Additionally, I also tested the inverse model in MATLAB in advance, and it behaved correctly there. But, since MATLAB updates variables sequentially accroding to my codes, while LTspice seems uses matrix-based solving, I wonder if it might be affecting the results. Do you have any suggestions?
Re: Non-converging oscillation problem of inverse Jiles-Atherton model in LTspice

 

Hi.
I managed to make a Jiles-Atherton model in LTspice. I also made a model taking into account the non-magnetic gap, and also derived H and B. I posted models on this forum. I also made the Jiles-Atherton model in Qspice.
Re: LTspice accuracy, used for calculations and measurements

 

Thank you Andy for your explanations.
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I will post results observed from other user for different LTspice versions as soon as possible.
----
Udo
Non-converging oscillation problem of inverse Jiles-Atherton model in LTspice

 

Hi all,

I¡¯m implementing an inverse Jiles-Atherton model in LTspice, mainly based on this paper:

The simulation stops around a quarter cycle. It seems to get stuck when "dH/dt" approaches zero ¡ª likely because of? "delta", which is the sign of "dH/dt"

I¡¯ve tried replacing the "delta" with a smooth "tanh" function, but the oscillation and convergence issue still remains.

Any suggestions on how to solve this problem?? I've posted my schematic here: /g/LTspice/files/Temp/invJAmodel_dynamictest.zip

Thanks!
Re: LTspice models do not work in Qspice

 

Hi Andy,
When I updated Qspice to the latest version I was able to run the simulation example for UCC27282 sent to me from Qspice forum (not my own one but one uses half bridge only), so that drew me to the conclusion that i had to rebuild/resimulate my file with the updated version of Qspice , I want to mention here that I copied and pasted the model for UCC27282 from the example I was sent by Q form into my own simulation that makes two of UCC27282, also I used different MOSFETs (4 of them) which I got from Qspice built in library:
BSC070N10NS5
The rest I had to place my self, only at this point the simulation was ok and the waveform screen appeared, it gives you a set of errors but it overrides them and simulation runs smoothly!
I could not upload my simulation file to Qspice it says that I have to earn few badges to do that!
Regards,
Suded
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