Re: Sine modulated PWM voltage source (PWL file=xxx)
This is a test, whether both of my emails now work. Please ignore
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Christoph,
?
Off-topic:
?
By the way, you can register your other email address that you used earlier today that bounced.? Then you can send messages to this group from your university address and they won't bounce.? It is known as an "Email Alias" for purposes of these groups.
?
To do that, go to the LTspice group webpage, then click your name in the upper right corner and choose "Settings".? Or go directly to .??Then scroll down to "Advanced Settings for Email Aliases" and click there.? Then type your alternate email address into the box above the "Add Email Alias" button, and then click that button. ?
Adding an Email Alias tells the [LTspice] group server to accept emails send from your Alias address as if it was sent from the address you normally use for this group, and it won't bounce.
?
From Groups Help:
If the email provider you use for your account sends your outgoing messages from an address that is different from your account address, or if you want to be able to send messages to groups from an additional address (for example, a work address) that is different from your account address, you can add an email?alias?to your account:
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Andy
?
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Re: integrate components from Texas Instruments
On 26/04/2025 13:31, patrick.kasten22
via groups.io wrote:
I uploaded the
library file under 'files'; I'm still not quite familiar with the
forum here. The IC in question is the LMR51635XF. But in general,
I have trouble properly integrating ICs, especially from Texas
Instruments.
BTW, it's best to send a separate message if you upload something to
Files > Temp. Most people do not see the automatically generated
message if you check the "Notify Members" box. If you? know how to
do it, it's also helpful to include a link to the uploaded file in
that message.
--
Regards,
Tony
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Re: integrate components from Texas Instruments
On 26/04/2025 13:31, patrick.kasten22
via groups.io wrote:
I uploaded the
library file under 'files'; I'm still not quite familiar with the
forum here. The IC in question is the LMR51635XF. But in general,
I have trouble properly integrating ICs, especially from Texas
Instruments.
You cannot use this model file with LTspice. It is encrypted and
will only work with PSpice. Similarly, if you? encrypt a model with
LTspice, that cannot be used with any other simulator.
I didn't check, but I suspect all 5 of the models TI lists on the
LMR51635** product page are encrypted. Looks like you're out of
luck.
Similarly, I didn't check whether ADI/LT offered a similar product
with a model that would work LTspice.
--
Regards,
Tony
|
Re: integrate components from Texas Instruments
I uploaded the library file under 'files'; I'm still not quite familiar with the forum here. The IC in question is the LMR51635XF. But in general, I have trouble properly integrating ICs, especially from Texas Instruments.
|
Re: integrate components from Texas Instruments
On 26/04/2025 12:32, patrick.kasten22
via groups.io wrote:
Hi, I'm new to
the group and also still a beginner with LTspice. I'm currently
using LTspice 24.0.12 ¡ª should I rather download the newer
version?
My actual problem is that I want to integrate components from
Texas Instruments. I followed this video: .
One thing that's different for me: when I click "Create a Symbol,"
I have to manually save it. I've always saved it in the lib/sym
folder. Otherwise, I¡¯m doing everything the same.
It sometimes works with simple components, but with ICs I often
get error codes.
Is there a new method for this?
It would be simpler if you just said which component you're trying
to make a symbol for. You're getting errors? What errors? We usually
don't advise trying to follow Youtube videos, because they're often
wrong, and the advice often poor. The first place to look is
LTspice's Help manual. It's not an easy read, but contains most of
what you need to know.
Anyhow...
There's basically a choice of two ways you can make a symbol for a
model that you have.
- Draw the symbol outline manually. Add the pins. Save the
symbol.
- Use LTspice to "Autogenerate" a symbol.
It sounds like you're using the first method. That's good, because
at you have control over what the symbol looks like. For method (2),
LTspice simply generates a rectangular symbol with the and arbitrary
pin layout. It also automatically saves it in the
\lib\sym\AutoGenerated folder. Unfortunately, it also hard-codes the
ModelFile attribute to that folder on your computer, so nobody else
can use it unless you (or they) edit the symbol.
You can, of course, combine the methods: let LTspice autogenerate
the symbol, but then you can manually edit the symbol and move the
pins where they makes sense, or to match the package, or whatever
other criterion you choose. Then, you can re-save the edited symbol
(manually) wherever it makes sense, which can be in the same folder
as the schematic? schematic that uses it, together with the model.
But you could save it anywhere you choose, but preferably not in the
same place as LTspice's own symbols. It is suggested to define a
separate folder where you keep your own symbols. You can tell
LTspice where that is in Control Panel > Search Paths.
The main issue with making your own symbol is getting the pin order
correct. Then it appears to simulate, but gives the wrong answers.
Another common error, is having a mismatch between the number of
pins in the symbol and the number defined in the model.
--
Regards,
Tony
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Re: integrate components from Texas Instruments
I strongly advise against YouTube videos.
Instead, follow the instructions in the LTspice Help
'Third-party models'. Do not add anything to LTspice native
files, because that makes your copy unique and will complicate
sharing files. You do not need to create symbols if an existing
symbol is usable. You do not need to update to the latest
version of LTspice, but you can.
If you get error codes after following the
above advice, please tell us exactly what they are.
On 2025-04-26 11:32, patrick.kasten22
via groups.io wrote:
Hi, I'm new to the group and also still a beginner with
LTspice. I'm currently using LTspice 24.0.12 ¡ª should I rather
download the newer version?
My actual problem is that I want to integrate components from
Texas Instruments. I followed this video: .
One thing that's different for me: when I click "Create a
Symbol," I have to manually save it. I've always saved it in the
lib/sym folder. Otherwise, I¡¯m doing everything the same.
It sometimes works with simple components, but with ICs I often
get error codes.
Is there a new method for this?
Thanks a lot!
--
Best wishes John Woodgate RAYLEIGH Essex OOO-Own Opinions Only
If something is true: * as far as we know - it's science *for
certain - it's mathematics *unquestionably - it's religion
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integrate components from Texas Instruments
Hi, I'm new to the group and also still a beginner with LTspice. I'm currently using LTspice 24.0.12 ¡ª should I rather download the newer version?
My actual problem is that I want to integrate components from Texas Instruments. I followed this video: .
One thing that's different for me: when I click "Create a Symbol," I have to manually save it. I've always saved it in the lib/sym folder. Otherwise, I¡¯m doing everything the same.
It sometimes works with simple components, but with ICs I often get error codes.
Is there a new method for this?
Thanks a lot!
|
Re: Sine modulated PWM voltage source (PWL file=xxx)
Thanks, Dennis, for pointing that out. At the moment I'm trying to get the points row defined by fixed time points with relative steps between each new pulse.It is allowed to change between absolute and relative timepoints, right? Is the unit "u" or "us" in the format of the time values?
It seems that the error occurs after 64 steps:
0.00423177 is not before 0.00423177
I uploaded the project file and a little explanation. Thanks.
-- Christoph
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On Fri, Apr 25, 2025 at 07:49 AM, Christoph wrote: I'm assuming that the file format is ... The file format is described in the LTspice help (Help->LTspice Help or F1) under Circuit Elements -> Voltage Source in the section Arbitrary Piece-Wise Linear Voltage Source. ? There is no structure to the sequence of datapoints. Each point defines the voltage at a point in time. LTspice connects these points with straight lines from the previous point. The PWL source has no knowledge of Trise, Ton, Tfall, or Toff. It's just a sequence of (time, voltage) pairs.? ? The FILE=<filename> format just allows the (time, voltage) pairs to be read in from a file rather than included directly on the spice line that defines the voltage source. ? There are a few features which allow easier definition of the time points, most importantly, a "+" before the time value defines a relative time, the given value is the difference between the new time point and the previous time point. There is also an option for a TIME_SCALE_FACTOR parameter on the PWL source which could be set to 1u to define all your times in microseconds rather than seconds, so you don't? need the "u" multiplier on each time point value.?? ? As others have said, if you want to define pulsed waveforms you should perhaps look at the section Time-Dependent Pulsed Voltage Source earlier in the same help page. ? ?
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Re: Diode TVS like zener in LTspice??
Andy,
you're not quite right. Here is my clarification:
.model SMBJ24CA D(Ron=.65 Roff=50Meg Vfwd=25 epsilon=6 Vrev=25 revepsilon=6 Vpk=24 mfg=Littlefuse type=TVS)
.model SMCJ33A D(Ron=.4 Roff=8Meg Vfwd=.7 epsilon=100m Vrev=38.65 Vpk=33 revepsilon=4 mfg=Littlefuse type=TVS)
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Re: Sine modulated PWM voltage source (PWL file=xxx)
Thanks, Andy. I¡®m after it. Probably my formula is producing this wrong input. And what my confusion about the file syntax is concerned, I¡®m on track again . I was totally besides the rails :) It¡®s indeed pointwise drawing the curve. I was drawing one pulsetrain per line:
tr/tf=trise/tfall Starting time 0V time+tr high 5V time+tr+ton 5V time+tr+ton+tf 0V
Still gotta find the error in the generator. ¡ª Christoph?
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Am 25.04.2025 um 13:34 schrieb Andy I via groups.io <AI.egrps+io@...>:
? Christoph,
?
In the first of the two files you uploaded (kuku_pwm_pulses.txt.zip), you have some data points that are not sequential.? The very first line is this:
0.000us 0 +0.010us 5 +0.000us 5 +0.010us 0?
which has a point at 0.000 us, then one at 0.010 us, then another at 0.010 us, and one at 0.020 us.? The second and third points are a problem because they are both at the same moment in time, not incrementally increasing.? Fortunately they both have the same voltage or current value (5 V or 5 Amps), but it is fundamentally in error for duplicating a time point.
?
That might be the cause of an error.? Hard to say for sure.
?
But later in the file, I see lines such as these:
8398.438us 0 +0.010us 5 +-1.598us 5 +0.010us 0?
8463.542us 0 +0.010us 5 +-3.195us 5 +0.010us 0?
and those are surely wrong.? ?The time increments are negative, coming before the previous time points.? Those need to be fixed.? (They are also confusing to read, so there is that too.)
?
Andy
?
?
|
Re: Sine modulated PWM voltage source (PWL file=xxx)
Christoph,
?
Off-topic:
?
By the way, you can register your other email address that you used earlier today that bounced.? Then you can send messages to this group from your university address and they won't bounce.? It is known as an "Email Alias" for purposes of these groups.
?
To do that, go to the LTspice group webpage, then click your name in the upper right corner and choose "Settings".? Or go directly to .??Then scroll down to "Advanced Settings for Email Aliases" and click there.? Then type your alternate email address into the box above the "Add Email Alias" button, and then click that button. ?
Adding an Email Alias tells the [LTspice] group server to accept emails send from your Alias address as if it was sent from the address you normally use for this group, and it won't bounce.
?
From Groups Help:
If the email provider you use for your Groups.io account sends your outgoing messages from an address that is different from your account address, or if you want to be able to send messages to groups from an additional address (for example, a work address) that is different from your account address, you can add an email?alias?to your account:
?
Andy
?
|
Re: Sine modulated PWM voltage source (PWL file=xxx)
On Fri, Apr 25, 2025 at 09:59 AM, Christoph wrote:
could it be that I'm assuming a different file format as I posted in the other email:
File format?? No.? The file formal for a PWL file is ordinary text.
?
Data format?? Possibly.
?
PWL data is always pairs of numbers, where the first number of the pair is time, and the second number is the voltage or current.? This is very well documented and every SPICE since the beginning of time uses the same format.
Syntax: Vxxx n+ n- PWL(t1 v1 t2 v2 t3 v3...)
Note that "t1 v1" is the first pair, "t2 v2" is the second pair, and so on.
?
PWL means "piece-wise linear".? The data points describe a set of points, and then LTspice "connects the dots" between the points, giving you a piece-wise linear waveform.
?
Timepoint ??????????????????????????V0 Trise. ??Von Ton ?????????????????????????????????????V? ?Tfall ??????Toff
0.000000000000000000us 0 ?0.010us 5 ???32.552083333333335702us 5 ??0.010us 0
I don't know where you got that from, but it definitely does not describe PWL.? That is similar to the description of a SPICE "PULSE" source, not PWL.? But it is incorrect for PULSE too.? I think it is not any SPICE syntax.
?
Some (undocumented) data formatting?
PWL is not "undocumented".? What you used above is undocumented, and incorrect, and definitely will not work for a PWL file.
?
Andy
?
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Re: Sine modulated PWM voltage source (PWL file=xxx)
On Fri, Apr 25, 2025 at 07:49 AM, Christoph wrote:
I'm assuming that the file format is ...
The file format is described in the LTspice help (Help->LTspice Help or F1) under Circuit Elements -> Voltage Source in the section Arbitrary Piece-Wise Linear Voltage Source.
?
There is no structure to the sequence of datapoints. Each point defines the voltage at a point in time. LTspice connects these points with straight lines from the previous point. The PWL source has no knowledge of Trise, Ton, Tfall, or Toff. It's just a sequence of (time, voltage) pairs.?
?
The FILE=<filename> format just allows the (time, voltage) pairs to be read in from a file rather than included directly on the spice line that defines the voltage source.
?
There are a few features which allow easier definition of the time points, most importantly, a "+" before the time value defines a relative time, the given value is the difference between the new time point and the previous time point. There is also an option for a TIME_SCALE_FACTOR parameter on the PWL source which could be set to 1u to define all your times in microseconds rather than seconds, so you don't? need the "u" multiplier on each time point value.??
?
As others have said, if you want to define pulsed waveforms you should perhaps look at the section Time-Dependent Pulsed Voltage Source earlier in the same help page.
?
?
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Re: Sine modulated PWM voltage source (PWL file=xxx)
I'm having internet connectivity problems. Resorting to my cell phone but cannot upload anything right now.
I'm assuming that the file format is
Timepoint V0 Trise. Von Ton V? Tfall Toff
0.000000000000000000us 0 0.010us 5 32.552083333333335702us 5 0.010us 0
The error is:
PWL time, value pairs out of chronological order in source V1
3.25521e-005 is not before 1e-008
it already occurs on the first line.
--
Christoph
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Am 25.04.2025 um 12:09 schrieb Christoph via groups.io <kuku@...>:
Am 25.04.2025 um 11:49 schrieb Mathias Born via groups.io <mathias.born@...>:
I'm really trying hard to make the error messages clear, but there is always room for improvement.
The message "time value pairs for V1 out of chronological order" means that there are at least two pairs (t1,y1) and (t2,y2) where t2<=t1.
It's difficult to find the location in the generated data. Easier it would be to avoid the situation at the side where the data is generated.
--
Christoph
Best Regards,
Mathias
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Re: Sine modulated PWM voltage source (PWL file=xxx)
Andy,
could it be that I'm assuming a different file format as I posted in the other email:
Timepoint ??????????????????????????V0 Trise. ??Von Ton ?????????????????????????????????????V? ?Tfall ??????Toff
0.000000000000000000us 0 ?0.010us 5 ???32.552083333333335702us 5 ??0.010us 0
Some (undocumented) data formatting? My idea was, that the first parameter is the proceeding point on the time axis, followed by the start voltage, the rise time, the on voltage, the on-time, followed by another voltage (at the end of the pulse), then the fall time and the off voltage.
I built that python program about a year or two ago and I think that file format could be sprung of a discussion here and someone pointed me to "undocumented" PWL file formats.?
I may be totally wrong and that example may have only worked before (with other data) by accidence :)
-- Christoph
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Just to be clear, those two lines of data look like this:
8398.438us 0
+0.010us 5
+-1.598us 5
+0.010us 0?
8463.542us 0
+0.010us 5
+-3.195us 5
+0.010us 0?
which then expands into this:
8398.438us 0
8398.448us 5
8396.850us 5? ?; This one is earlier than the one above it
8396.860us 0?
...
?
Andy
?
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Re: Sine modulated PWM voltage source (PWL file=xxx)
I'm having internet connectivity problems. Resorting to my cell phone but cannot upload anything right now.
I'm assuming that the file format is
Timepoint V0 Trise. Von Ton V? Tfall Toff
0.000000000000000000us 0 0.010us 5 32.552083333333335702us 5 0.010us 0
The error is:
PWL time, value pairs out of chronological order in source V1
3.25521e-005 is not before 1e-008
it already occurs on the first line.
--
Christoph
toggle quoted message
Show quoted text
Am 25.04.2025 um 12:09 schrieb Christoph via groups.io <kuku@...>:
Am 25.04.2025 um 11:49 schrieb Mathias Born via groups.io <mathias.born@...>:
I'm really trying hard to make the error messages clear, but there is always room for improvement.
The message "time value pairs for V1 out of chronological order" means that there are at least two pairs (t1,y1) and (t2,y2) where t2<=t1.
It's difficult to find the location in the generated data. Easier it would be to avoid the situation at the side where the data is generated.
--
Christoph
Best Regards,
Mathias
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Re: Sine modulated PWM voltage source (PWL file=xxx)
Mathias, The error message clearly led me to the correct guess of the problem, time sequence out of order or unrealizable (zero or negative time step).??
Christoph, I've never used a text file to generate a PWM signal.? I suppose it'd be handy to generate a random bit, or send in a bit of audio or a modulating waveform.? For a simpler PWM signal, I'd suggest using a PULSE source (V or I), and building the first period of the waveform in the setup, and then entering a value for the Period, which will cause the waveform to repeat indefinitely if all is set up right.? An example statement:
PULSE (0 {Clock_Vhi} 0 100n 100n 2.5u 5u)
generates a 200kHz clock with 50% duty cycle, Vlo=0, Vhi=(Passed in parameter, defined by statement .param Clock_Vhi = 3.3), 100ns rise & fall times, 2.5microsecond time at Vhi, 5microsecond period. The LT Spice XVII help documentation covers this well.? ? I'm still getting used to the new key bindings and help system in LT Spice 24 (keep learning, or get run over!). -Rick, WA2YMS (an occasional contributor)
On Friday, April 25, 2025 at 07:48:14 AM EDT, Andy I via groups.io <ai.egrps+io@...> wrote:
On Fri, Apr 25, 2025 at 06:07 AM, Christoph wrote:
Forgot the mechanism how uploads work here. Is the group notified automatically when an upload occurs?
No, not necessarily.? There is a checkbox when you upload, which sends an auto-generated message, which most everyone ignores, and it self-destructs in a few days.? We ask that you always compose and send a real message here, in your message thread, not the auto-generated one, telling us what you uploaded (and why, if it's not obvious).
?
Andy
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Re: Sine modulated PWM voltage source (PWL file=xxx)
On Fri, Apr 25, 2025 at 06:07 AM, Christoph wrote:
Forgot the mechanism how uploads work here. Is the group notified automatically when an upload occurs?
No, not necessarily.? There is a checkbox when you upload, which sends an auto-generated message, which most everyone ignores, and it self-destructs in a few days.? We ask that you always compose and send a real message here, in your message thread, not the auto-generated one, telling us what you uploaded (and why, if it's not obvious).
?
Andy
|
Re: Sine modulated PWM voltage source (PWL file=xxx)
Just to be clear, those two lines of data look like this:
8398.438us 0
+0.010us 5
+-1.598us 5
+0.010us 0?
8463.542us 0
+0.010us 5
+-3.195us 5
+0.010us 0?
which then expands into this:
8398.438us 0
8398.448us 5
8396.850us 5? ?; This one is earlier than the one above it
8396.860us 0?
...
?
Andy
?
|
Re: Sine modulated PWM voltage source (PWL file=xxx)
Christoph,
?
In the first of the two files you uploaded (kuku_pwm_pulses.txt.zip), you have some data points that are not sequential.? The very first line is this:
0.000us 0 +0.010us 5 +0.000us 5 +0.010us 0?
which has a point at 0.000 us, then one at 0.010 us, then another at 0.010 us, and one at 0.020 us.? The second and third points are a problem because they are both at the same moment in time, not incrementally increasing.? Fortunately they both have the same voltage or current value (5 V or 5 Amps), but it is fundamentally in error for duplicating a time point.
?
That might be the cause of an error.? Hard to say for sure.
?
But later in the file, I see lines such as these:
8398.438us 0 +0.010us 5 +-1.598us 5 +0.010us 0?
8463.542us 0 +0.010us 5 +-3.195us 5 +0.010us 0?
and those are surely wrong.? ?The time increments are negative, coming before the previous time points.? Those need to be fixed.? (They are also confusing to read, so there is that too.)
?
Andy
?
?
|
Christoph
Tony Casey
John Woodgate