Re: Models LM317 and LM337 made by the same hand
For what its worth they probably won't behave exactly the
same in a real design.
There's generally a preference for NPN transistors as power
elements, meaning that positive side regulators are based on
emitter followers and negative regulators are common emitter. This
means the negative regulator will typically have more complicated
output stability limitations.
I remember discovering at least one make of 7915 regulator could
produce a sawtooth output if the bypass capacitance fell in a
certain critical range.
On 03/02/2025 08:31, andrea.patuelli
via groups.io wrote:
toggle quoted message
Show quoted text
Hi to all.
I'm searching two model LM317 and LM337 exatly mirrored made
by the same hand. I already done a tes with two models pick up
separatly but they give me different output .
I'm building a DUAL POWER SUPPLY and I would verify the good
functioning of all parts adding the trik to arrive 0V
(TLV431-1,25V).
Any suggestion will be appreciaded.
Many thanks
Andrea
|
Re: In need of some zeners or maybe model them myself
On 2025-02-04 01:00, Ivan via groups.io
wrote:
On Mon, Feb 3, 2025 at 04:46 PM, John Woodgate wrote:
The first step is to
search the groups archives from the web site Files page.
Then ask the manufacturer, found by a web search - STI in
the case of the 1N4572, Microchip for 1N5226, etc.
I tried the group archives a couple of different ways but was
unsuccessful. As far as STI, what is that an acronym for again?
As far as Microchip, their site has not been helpful so far. Got
the data sheet but, can't find a spice file. Tried it again just
now and, still no spice file. As with most data sheets, I
believe I have most of what I need to model my own if I have to.
Thoughts? In the meantime, let me know about STI.
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
Re: In need of some zeners or maybe model them myself
Which country are you in? I know of a British
supply of the power transistor at a very low price,
comparatively, but not for export.
On 2025-02-04 00:23, Ivan via groups.io
wrote:
On Mon, Feb 3, 2025 at 04:57 PM, Tony Casey wrote:
Wow! Have you seen the price of 2N3791s? They
haven't been made for decades. Why are you using them?
--
Regards,
Tony
?
I'm actually trying to simulate a device we make at work. I work
at a small company and their stuff is old as hell. Lol! The
company has been around for 40 or so years so, a lot of the
devices were designed with really old components and..., they've
never been updated. In my department specifically, we still used
DOS programs up until our testing rig died about two years ago.
Lol! Every so often something goes obsolete and the department
head has to scramble to find a replacement. Unfortunately, most
of our stuff has to meet government standards so, changing one
component to another is a real PITA and, time consuming. Worse
still, they fired their last engineer here about two years ago
so, no one actually knows how any of our products really work at
the deepest component level. Don't know how the company is
staying afloat. In any case, I am trying to up my game some to
eventually ask for more money. :) We're mostly in production
mode all the time but, quite often we also have to troubleshoot
and fix stuff. Most are easy fixes but, this one device has been
a mystery to us all. Not completely but, enough where we just
don't know what to make of certain anomalies when they pop up.
Either way, if I could simulate this device, I think it'll
really help me understand some things better.
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
Re: In need of some zeners or maybe model them myself
Hi Ivan,
?
I've uploaded a zip file - some-zener-models.zip - with 2 files in it. The Cordell text file I might have downloaded from here, can't remember.
?
The 1N5241B is in both files. There may be some equivalents you can use.
?
--
--
Regards,
Abes
|
Re: Models LM317 and LM337 made by the same hand
|
Re: Creating My Own Library
Sorry folks, the example project is here.
?
?
Sent:?Monday, February 03, 2025 at 11:18 PM
From:?"eewiz via groups.io" <eewiz@...>
To:[email protected]
Subject:?Re: [LTspice] Creating My Own Library
Hello all:
?
Ivan, I have uploaded an example project that details how to create a single symbol that permits selection of multiple sub-circuit models.
Many thanks to Andy I for his library management Example 3 that got me started.
?
All for now
?
?
Sent:?Monday, February 03, 2025 at 8:43 PM
From:?"Ivan via groups.io" <1van4ocker@...>
To:[email protected]
Subject:?Re: [LTspice] Creating My Own Library
Just to add to what Andy has said, your personal *.bjt, *.mos etc files will only show up in the "Pick New Transistor (etc.)" dialogue if you place your user.bjt (etc.) files in:
C:\users\<username>\Documents\LTspice
I'm happy to report that I haven't had any issues after creating a user.bjt and user.dio file that are placed in the Documents\LTSpice folder so now, when I choose to "pick new diode" or "pick new transistor", they are there. Only issue I have is that LTSpice seems to pick their version over my version if they have the same name. I noticed (thanks to Andy for pointing this out) that when I retrieve the Spice Netlist to see what the .inc statements are, LTSpices' comes first and then, my Documents\Ltspice file comes after. I'm guessing I could change the name of my diode (in this case) slightly and that would take care of the problem. yes? Otherwise..., all good.
Any models that are actually a .subckt will not show up in this dialogue.
Yep. I finally got that bit. Lol!
|
Re: Creating My Own Library
Hello all:
?
Ivan, I have uploaded an example project that details how to create a single symbol that permits selection of multiple sub-circuit models.
Many thanks to Andy I for his library management Example 3 that got me started.
?
All for now
?
?
Sent:?Monday, February 03, 2025 at 8:43 PM
From:?"Ivan via groups.io" <1van4ocker@...>
To:[email protected]
Subject:?Re: [LTspice] Creating My Own Library
Just to add to what Andy has said, your personal *.bjt, *.mos etc files will only show up in the "Pick New Transistor (etc.)" dialogue if you place your user.bjt (etc.) files in:
C:\users\<username>\Documents\LTspice
I'm happy to report that I haven't had any issues after creating a user.bjt and user.dio file that are placed in the Documents\LTSpice folder so now, when I choose to "pick new diode" or "pick new transistor", they are there. Only issue I have is that LTSpice seems to pick their version over my version if they have the same name. I noticed (thanks to Andy for pointing this out) that when I retrieve the Spice Netlist to see what the .inc statements are, LTSpices' comes first and then, my Documents\Ltspice file comes after. I'm guessing I could change the name of my diode (in this case) slightly and that would take care of the problem. yes? Otherwise..., all good.
Any models that are actually a .subckt will not show up in this dialogue.
Yep. I finally got that bit. Lol!
|
Re: Any Good Reason to Plumb Ground Out of Hier. Schem.
On Mon, Feb 3, 2025 at 08:26 PM, eewiz wrote:
Is there any good reason to plumb the ground net (node 0) out of a hierarchical schematic block?
Inside the block, the hierarchical label could be called RTN and outside the block, the hierarchical label could be connected to ground (node 0).
Assuming it is always connected to node 0 outside the block, it appears to me that there is no good reason to do the plumbing.
There are actually some "tricks" going on, when a subcircuit (or lower-level schematic) has a "ground" net that comes out on a .subckt pin.? Some years ago I spent some time documenting this, but did not finish.
?
When a subcircuit has its "ground" pin brought out to the higher-level, and if that pin is not connected to node 0 / ground at the higher level, then the internal "ground" is no longer ground.? It becomes whatever that pin connects it to.
?
This is particularly useful when you inherit a subcircuit model from someone else, which has internal points connected to ground, but you don't want to use it that way.? Say that you have an IC that is "normally" powered by +5 V and ground.? The guy who made the SPICE model might have written it so that the "ground" pin goes to node 0 inside their subcircuit model.? But you might want to use it powered by +2.5 and -2.5 V.? In the old days, what we had to do was re-write the vendor's SPICE model, changing all their node 0 netnames to something else, so that it could be NOT connected to ground.? What LTspice allows you to do, is just bring that net out on a pin, letting you use it as if it was not node 0.
?
This looks wrong, because the lower-level schematic (or .SUBCKT block) seems to be using node 0, but it actually isn't.? LTspice handles the net name translation automagically.
?
By the way, I am not sure if everyone here understands your use of the words "plumb" or "plumb out".? Honestly, I am not sure that I know exactly what you mean either.? Remember that a sizable percentage of?the members of this group are not in North America and do not know our slang.
?
Node 0 is the only universal node.
Except when it isn't.
?
If I remember correctly, LTspice uses "GND" as an alias for node 0, but not "ground", and not nodes 00 or 000.? The fact that node "ground" is not the ground node (node 0) can be a little confusing, because LTspice displays that both of them are ground if you hover over them, but one is "ground" while the other is "node ground".
?
Andy
?
|
Re: Models LM317 and LM337 made by the same hand
On Mon, Feb 3, 2025 at 04:53 PM, Bell, Dave wrote:
I just uploaded the file, Dual PSU simplified.zip
Your upload seems to be missing the LM337 symbol.? And its model too.
?
And it is not a Dual PSU.? Did you upload the wrong thing?
?
IMO, it is dangerous defining a new model for the BZX84B33VLY.? LTspice already has that model in its library.? Unless you are using version 24.1.1, how do you know which model is used?? They are immensely different.
?
Andy
?
|
Re: Models LM317 and LM337 made by the same hand
On Mon, Feb 3, 2025 at 04:53 PM, Bell, Dave wrote:
I couldn¡¯t read the part number of the? three terminal reference diode, ...
It looks to me like TLV431AS, making it another member or derivative of the TL431 family.? Connected this way, it would be 1.24 V.
?
Also, had to assume the output was to be 3.3V, based upon the Zener on the output.
I don't quite follow.? The zeners on the output are 33 V (+/- 0.7), so I think the regulated output could approach 30 V based on that alone.
?
Andy
?
|
Re: In need of some zeners or maybe model them myself
FYI -
?
I made some changes to one of my previous replies, which mostly do not affect this discussion, but I want to be more correct about them.
?
In most common usage, -55 to +100 C would be somewhere between Industrial and Military Grade.? 0 to +75 C would be Commercial grade.
?
Andy
?
|
Re: In need of some zeners or maybe model them myself
I don't remember if I replied to this already:
?
I tried the group archives a couple of different ways but was unsuccessful.
The key was to strip off the "A" or "B" suffix.
?
Searching for "1N5226B" fails.
Searching for "1N5226" succeeds.
?
The 1N5226 is the more common diode, for most of us who don't build for the U.S. military.? The 1N5226B (supposedly) goes through more thorough testing and more steps and documentation, jacking up its price.? It is probably the same exact die coming out of the furnace.
?
Andy
?
|
Re: In need of some zeners or maybe model them myself
On Mon, Feb 3, 2025 at 08:11 PM, Ivan wrote:
It was just a long string of words without any separation. I copied and pasted it off some posting from a link on some spice model site.
Not even spaces?? Wow.
?
Often a text file displays incorrectly in Notepad because it appears to be missing linefeeds, turning it into one run-on sentence or long paragraph, but the spaces between words and fields would still be there.? It doesn't really matter, but can you make out words?
?
It wasn't an olb file.
I did not mean that, FYI.? AFAIK, .olb files are not encrypted; they are binary.? I believe they are symbol files, giving them similar functionality as LTspice's .asy files.? PSpice uses .olb files.? LTspice does not.? Since they are symbol files, they are not the SPICE model.? They probably describe the shape and appearance of the object on your schematics.
?
Andy
?
?
|
Re: In need of some zeners or maybe model them myself
On Mon, Feb 3, 2025 at 08:00 PM, Ivan wrote:
As far as STI, what is that an acronym for again?
I think that is the name of a company.? I wonder if John meant STM (STMicroelectronics)?? (There is an STI that makes thermocouples.)?
CORRECTION:? The company name John refers to is ST, also known as ST Micro or ST Microelectronics NV.? They sometimes use the abbreviation STM and sometimes just ST, as in their website presence, and perhaps STI although I did not find that one.? Their website is .
?
I am not getting STI from Google searches of that zener.? But I did get a hit from Microsemi ().? I do not see a link to or mention of a SPICE model on that page but I did not try looking harder.? When that happens, sometimes one needs to contact the manufacturer and ask if they have one.? I think that is probably not needed now.
?
Manufacturers might give you very little information about old or rarely used parts.
?
FYI, Microsemi's datasheet says the difference between the 1N4572 and 1N4572A is the temperature range.? The "A" version is spec'd from -55 to +100 C (Miliitary Industrial or Military grade), whereas the non-A is from 0 to +75 C only (Consumer Commercial grade).? Same device, but different guarantees --> higher price.
?
Andy
?
|
Re: In need of some zeners or maybe model them myself
On Mon, Feb 3, 2025 at 07:40 PM, Ivan wrote:
I searched the vendor sites but have so far come up empty. I will try again. I did also search on this site but, nothing came up for any of these parts.
I think it is critical to omit the suffix letters when searching.? I do not claim there is no difference between a 1N4572 and a 1N4572A, but sometimes the only difference is either (1) it is in a different package, or (2) the "A" or "B" version is guaranteed to meet its specs over a wider or narrower temperature range.
?
When John Woodgate said he found two of them on the Internet, that gives me hope, and says you probably missed them.
?
I can check the data sheets to see if there are any differences but, even if it does, and I do find a model file like the one you posted below, can't I just change the one or two parameters that may be different in the datasheets and then, after updating the model file, save the model file under a new model name?
Sure.
?
Be aware that SPICE model parameters usually do not correspond directly to datasheet specs.
?
Anyway, even if a 1N4572 and a 1N4572A actually are different, I would not expect their differences to be as much as between a 1N4572A and a 1N5226B.? ?Chances are very good that the same SPICE model works equally well for both.? No SPICE model matches 100% (and no two samples match each other 100%), but I would kind of expect that one SPICE model is equally close to both 1N4572A and 1N4572.
* 1N5226 ? ?3.3 Volt ?5% ?W zener diode
.model D1N5226 ?D(Is=31.47f Rs=9.494 Ikf=0 N=1 Xti=3 Eg=1.11 Cjo=220p M=.5959
+ ? ? ? ? ? ? ? Vj=.75 Fc=.5 Isr=2.035n Nr=2 Bv=3.3 Ibv=45.862m Nbv=3.0477
+ ? ? ? ? ? ? ? Ibvl=29.831m Nbvl=11.606 Tbv1=-636.36u)
* ? ? ? ? ? ? ? Motorola ? ? ? ?pid=1N5226 ? ? ?case=DO-35
* ? ? ? ? ? ? ? 89-9-18 gjg
* ? ? ? ? ? ? ? Vz = 3.3 @ 20mA, Zz = 310 @ 1mA, Zz = 68 @ 5mA, Zz = 19 @ 20mA
?
This looks like a PSpice file, no?
Well, yes, and no.? It is a SPICE model.? That makes it a PSpice model, and an HSPICE model, and an LTspice model, and everybody else that makes SPICE programs.
?
From what I understand, LTSpice can read them no problem, right?
Yes.? LTspice is SPICE and it reads SPICE models.? Every parameter above is understood and used by LTspice.? They are SPICE diode model parameters, after all.
?
Notice that the last 3 lines are comment lines (ignored by SPICE and LTspice and PSpice and ...).
Or, do I have to remove that first D in the name, for example, in order for LTSpice to recognize it?
Keep it or delete it, whatever you choose.? LTspice recognizes alphanumeric names.? Old versions of SPICE (and programs derived from it) required a letter as the first character, which is why you occasionally find model names like that.? But LTspice doesn't care.
?
I'm assuming I just copy and paste this into a text file and name it 1N5226.lib or .mod or something and try it out, no?
Pretty much, yes.? To just "try it out", indeed even to use it normally, it does not need to be in a separate file.? You could put it on the schematic itself, as a SPICE Directive.
?
If instead you save it to a separate text file, remember to include the file, with a ".inc" or ".lib" statement.
?
Andy
?
|
Re: Creating My Own Library
Why would you want to do that? Even with the .inc discretes.lib, if these .models don't appear in user.??? files in the correct place, you can't select them in the "Pick New Transistor/MOSFET/Diode/etc" list.
I kinda already responded to this just now but, just to reiterate, I'm not putting all my different model types in one user file in a "working environment" situation. As I mentioned in my last reply before this, I have all my transistors in one user.bjt file at the root of my Documents\LTSPice folder and, I have all my diodes in a user.dio file in the same place. I can successfully pick them when I'm going to "pick new whatever". Don't actually remember why I responded the way I did except that, I think what I meant to do was express that I thought that was a good idea, in regards to, "archiving' all the files together for managements sake and, for sharing the project if the need arises. Of course, now that I look at my response, I guess it was just me being an idiot at the moment. Lol! Sorry for the confusion. :)
The only advantage this method has is that it is easier to distinguish "your" models from those provided by ADI in the LTspice distribution. But you can also do that with models that appear in your user.??? files. You can add or change the manufacturer's name: Mfg=MyCollectedModels, so it stands out on the list, and can be selected from any of "your" models by clicking on the Manufacturer column.
I did that very thing to my user files. That is, I put mfg=me in them so, when I go to pick a new whatever, I can sort by manufacturer just like you said. All good. thanks.
|
Re: Creating My Own Library
Just to add to what Andy has said, your personal *.bjt, *.mos etc files will only show up in the "Pick New Transistor (etc.)" dialogue if you place your user.bjt (etc.) files in:
C:\users\<username>\Documents\LTspice
I'm happy to report that I haven't had any issues after creating a user.bjt and user.dio file that are placed in the Documents\LTSpice folder so now, when I choose to "pick new diode" or "pick new transistor", they are there. Only issue I have is that LTSpice seems to pick their version over my version if they have the same name. I noticed (thanks to Andy for pointing this out) that when I retrieve the Spice Netlist to see what the .inc statements are, LTSpices' comes first and then, my Documents\Ltspice file comes after. I'm guessing I could change the name of my diode (in this case) slightly and that would take care of the problem. yes? Otherwise..., all good.
Any models that are actually a .subckt will not show up in this dialogue.
Yep. I finally got that bit. Lol!
|
Any Good Reason to Plumb Ground Out of Hier. Schem.
Hello All:
?
Is there any good reason to plumb the ground net (node 0) out of a hierarchical schematic block?
Inside the block, the hierarchical label could be called RTN and outside the block, the hierarchical label could be connected to ground (node 0).
Assuming it is always connected to node 0 outside the block, it appears to me that there is no good reason to do the plumbing.
?
I understand that if the reference inside the block is not connected to node 0 outside the block then of course that inside reference would have to be plumbed to the outside of the block.
Node 0 is the only universal node.
?
Any horror stories either way?
?
All for now
?
?
|
Re: In need of some zeners or maybe model them myself
On Mon, Feb 3, 2025 at 05:46 PM, John Woodgate wrote:
Old Hi-Fi?
?
I wish. I'm a musician. Been through many tube guitar amps so I love them old radio engineers handbooks and the sort but alas. No. We make gas sensors to detect dangerous gases in industrial settings. Hence, the need for government standards.
?
|
Re: In need of some zeners or maybe model them myself
On Mon, Feb 3, 2025 at 04:54 PM, Andy I wrote:
On Mon, Feb 3, 2025 at 04:01 PM, Ivan wrote:
I did find one text doc that is supposed to be a library of models that includes the 1N5226B but, it's very difficult to see what is what in that file.
Beware.? There is at least one long list of library parts, which I've seen uploaded in this group a few times, but they are not the models.? It is just a list of the parts that you could get, if you installed a separate program or purchased someone's library.? I don't know if this is what you saw, but it might be.
It wasn't anything like that.
On the other hand, it could be a library of models.? If it seems difficult to read, it might be a text file formatting thing.? Some text files use CR/LF characters between lines, some use just CR or just LF, and some use LF/CR.? Windows's Notepad can't display all of them correctly.? Try another text editing program.
?
It was just a long string of words without any separation. I copied and pasted it off some posting from a link on some spice model site.
Another possibility is that it is an encrypted file, but that is less likely.
?
It wasn't an olb file. I have one of them from OnSemi or, OrCad or something. Sucks that I can't hack into that one. :) This file is in plain English. It definitely wasn't formatted hence, why I tried to bang it into something that looks like a library. Mainly, I'm trying to correlate what they seem to be describing as the parameters of the device, with the section where the parameters seem to be listed, if that makes any sense. I can copy and paste it into my next response. It isn't that long. Let me know.
|
John Woodgate
eewiz