开云体育

Dear All LTspice users:









Below you will find a link to a video that I created on the subject of
IMD, LTspice is used in part 1 (Part 2 confirms the theory of part 1 using
some lab experiments, is has not been released)



to perform simulations that confirm classroom theory.







Part 2 will have lab experiments using a spectrum analyzer, and the same
circuits that were used in part 1.





I expect to release part 2 next week.

















enjoy.





Sincerely,





Julio Rodriguez

Hello Helmut,



I did click on the box after 10 seconds, but only got 82 bytes as the
download using IE 10. I copied the address and used Chrome. Then I did get
the full 31.98 MB file download, must be something missing in my version of
IE10. Thank you for letting me know that the box was supposed to work.



Gene



From: LTspice@... [mailto:LTspice@...] On Behalf Of
Helmut
Sent: Saturday, July 06, 2013 3:38 PM
To: LTspice@...
Subject: [LTspice] Re: My collection of models and examples for LTspice.





Hello Gene,

You have to click the "button" below the 31.98. It's enabled
after 10 seconds.

Best regards,
Helmut

--- In LTspice@... <mailto:LTspice%40yahoogroups.com> , "Gene
Neau" <glneau@...> wrote:

Hello,

Neither this 31.98Meg nor the previous 98Meg files appear to have working
links. I see a timer that counts down and only when it reaches 0 is there

a

box that may be a link, but the downloaded file is an index.html of 1 kB.
Could you please provide more information on how to download the files.
Thank you.

Gene



From: LTspice@... <mailto:LTspice%40yahoogroups.com>

[mailto:LTspice@... <mailto:LTspice%40yahoogroups.com> ] On
Behalf Of

bordodynov
Sent: Thursday, July 04, 2013 11:55 PM
To: LTspice@... <mailto:LTspice%40yahoogroups.com>
Subject: [LTspice] My collection of models and examples for LTspice.





Hello All.
My collection of models and examples for LTspice contains a large number

of

models. It includes a collection of EXTRA. This collection EXTRA I

expanded

with new models and changed the characters of digital items. Now you do

not

need a reference to the library. The collection contains a lot of
operational amplifiers described in bulk (one character and a lot of
models). Also, it has a model of the photodiodes, avalanche photodiodes,
avalanche transistors, lasers, and many other items. In folder example a

lot

of good examples.
File is LTspiceIV.zip (34Meg).
Link --->

Bordodynov.

In message <5530A1C2-0298-4665-81A6-744C48C344EE@...>, dated Sat, 6 Jul 2013, Jim Wagner <wagnejam99@...> writes:

How much fluff would be added with a line in the help like:

SpiceLine: Vt=0.5 Vh=0.1m

1 millifluff. But there are a million examples with an equally good claim for inclusion, leading to a total of 1 killerfluff.

When someone does not use LTspice very often (in my case, intensively 2 or 3 times a year) I cannot even remember what the delimiters are between the values.

Me too, but it's just like trying to remember your French, Spanish, Inuktitut (think climate change) or whatever when you go on holiday.
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
Why is the stapler always empty just when you want it?

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

In message <kr9rri+fhu1@...>, dated Sat, 6 Jul 2013, analogspiceman <analogspiceman@...> writes:

Personally, I wish he would take out more of the random fluff from Help, so that at the top levels it would be more of a pure LTspice reference guide. But for each and every topic, Help should also include several clickable hotlinks to copious examples, both text and graphical. I don't see why it couldn't also include clickable links to open runnable schematic example files as well.

This would be good, but it's really a job for someone other than Mike, who has things to do that only he can do.

While this list has more than its fair share of philanthropes, it doesn't have one who has taken on the task of upgrading the Help as you propose.
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
Why is the stapler always empty just when you want it?

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

Hello Gene,

You have to click the "button" below the 31.98. It's enabled
after 10 seconds.

Best regards,
Helmut

Hello,

Neither this 31.98Meg nor the previous 98Meg files appear to have working
links. I see a timer that counts down and only when it reaches 0 is there a
box that may be a link, but the downloaded file is an index.html of 1 kB.
Could you please provide more information on how to download the files.
Thank you.

Gene



From: LTspice@... [mailto:LTspice@...] On Behalf Of
bordodynov
Sent: Thursday, July 04, 2013 11:55 PM
To: LTspice@...
Subject: [LTspice] My collection of models and examples for LTspice.





Hello All.
My collection of models and examples for LTspice contains a large number of
models. It includes a collection of EXTRA. This collection EXTRA I expanded
with new models and changed the characters of digital items. Now you do not
need a reference to the library. The collection contains a lot of
operational amplifiers described in bulk (one character and a lot of
models). Also, it has a model of the photodiodes, avalanche photodiodes,
avalanche transistors, lasers, and many other items. In folder example a lot
of good examples.
File is LTspiceIV.zip (34Meg).
Link --->

Bordodynov.

How much fluff would be added with a line in the help like:

SpiceLine: Vt=0.5 Vh=0.1m

When someone does not use LTspice very often (in my case, intensively 2 or 3 times a year) I cannot even remember what the delimiters are between the values. I (also do programming, professionally, and I can go, in the Language Reference, and find the syntax for the language I use).

One of the big attributes of LTspice is efficiency. Any time that you have to go to some other source (a Wiki, a Pspice manual, or such) is a hit on the productivity. This COULD be significantly improved for me by including a few examples, such as the one above, particularly where you have to provide the parameters or a model (such as SWITCH) in order to get it to work. And, for me, SWITCH is the worst of the worst because there is no default operation.

Thanks
Jim

On Jul 6, 2013, at 12:40 PM, analogspiceman wrote:

--- In LTspice@..., Jim Wagner <wagnejam99@...> wrote:

It would REALLY help if there were just examples in the Help.
How is it that you specify a SCHMITT or a SWITCH? It would take
very few such examples to help those of us who are not frequent
users or who do not have an encyclopedic memory.

LTspice Help is written primarily as a terse reference guide (with
a few examples thrown in). Usually all the information required
to use a feature is included, albeit in a very condensed form.
Mike has written Help like working programming code - you know all
the information must be there (since it works, at least for some),
but you must interpret each word as if you yourself were a compiler
digesting the code. This often requires many read-throughs of a
topic paying attention to the logical meaning of each word.

This works well for some and is in the spirit of a pure reference
guide akin to traditional programming language reference guides.
I know Mike does not want to bloat Help with lots of "fluff"
teaching examples so that it becomes difficult to find the "meat"
thereby degrading its usefulness as a reference.

Personally, I wish he would take out more of the random fluff from
Help, so that at the top levels it would be more of a pure LTspice
reference guide. But for each and every topic, Help should also
include several clickable hotlinks to copious examples, both text
and graphical. I don't see why it couldn't also include clickable
links to open runnable schematic example files as well.

[Non-text portions of this message have been removed]

--- In LTspice@..., "zeeglen" <glen@...> wrote:

Too bad this information is not easily found in the Help file.

Yes, Help, although fairly extensive, is not complete. The LTwiki
documents many of the missing items.

Since you seem willing and able, here is a big hint on how to use
LTspice itself to answer questions not answered in Help. Make sure
Generate Expanded Listings is enabled in the Control Panel. Then,
after you run a simulation with puzzling results, carefully examine
and compare the netlist (drop down menu item) and the *digested*
netlist that appears in the SPICE Error Log. That (an a little
experimentation) will inform you as to how LTspice deals with all
those SpiceLines, Values, and other such parameters.

--- In LTspice@..., Jim Wagner <wagnejam99@...> wrote:

It would REALLY help if there were just examples in the Help.
How is it that you specify a SCHMITT or a SWITCH? It would take
very few such examples to help those of us who are not frequent
users or who do not have an encyclopedic memory.

LTspice Help is written primarily as a terse reference guide (with
a few examples thrown in). Usually all the information required
to use a feature is included, albeit in a very condensed form.
Mike has written Help like working programming code - you know all
the information must be there (since it works, at least for some),
but you must interpret each word as if you yourself were a compiler
digesting the code. This often requires many read-throughs of a
topic paying attention to the logical meaning of each word.

This works well for some and is in the spirit of a pure reference
guide akin to traditional programming language reference guides.
I know Mike does not want to bloat Help with lots of "fluff"
teaching examples so that it becomes difficult to find the "meat"
thereby degrading its usefulness as a reference.

Personally, I wish he would take out more of the random fluff from
Help, so that at the top levels it would be more of a pure LTspice
reference guide. But for each and every topic, Help should also
include several clickable hotlinks to copious examples, both text
and graphical. I don't see why it couldn't also include clickable
links to open runnable schematic example files as well.

I have found the instance parameters and Spiceline and Spiceline2 to be totally incomprehensible. I think it assumes a familiarity with ancient_spice which Mike thoroughly refuses to detail in the Help File. At that point, I usually flounder and try, sort of pseudorandomly, until something appears to work.

It would REALLY help if there were just examples in the Help. How is it that you specify a SCHMITT or a SWITCH? It would take very few such examples to help those of us who are not frequent users or who do not have an encyclopedic memory.

That said, SCHMITT is like an inverter with input hysteresis defined. I don't remember the details but I think that you specify either the high and low trip points OR the hysteresis amplitude and the midpoint of the hysteresis window, or something like that. And, yes, you have to do it in a spiceline. Please don't ask me how!

Jim Wagner
Oregon Research Electronics

On Jul 6, 2013, at 11:18 AM, zeeglen wrote:

--- In LTspice@..., "analogspiceman" <analogspiceman@...> wrote:

--- In LTspice@..., "zeeglen" <glen@> wrote:

Can anyone explain why the difference between INV and SCHMITT?

Try reading the Help file next time before spamming the group with
your needlessly ignorant drivel. Quoting Help:

Actually, the Help file was the first place I went hunting and found this:

The Schmitt trigger devices have similar output characteristics as
the gates. Their trip points are specified with instance parameters
Vt and Vh. The low trip point is Vt-Vh and the high trip point is
Vt+Vh.

At that point I searched for "instance parameters", and one of the several pages I investigated was titled "Adding Attributes". That led to "General Attribute Editor" which displays a "Component Attribute Editor". Nowhere does it state what is meant by "Spiceline" or "Spiceline2".

That is when, as I described, I tried driving both INV and SCHMITT from the same sine wave voltage source and noted their switching voltage was identical. If so, why the difference in the circuit? That was my question.

I have since found more information online that actually clearly states how to input instance parameters using the Spiceline in the Component Attribute Editor. Too bad this information is not easily found in the Help file. Do not assume that those who come to this forum seeking assistance have not already attempted to find the answer. The reason they come to this forum is that have tried but not been able to find the answer.

[Non-text portions of this message have been removed]

--- In LTspice@..., "zeeglen" <glen@...> wrote:

Hi all. I've just uploaded a file "Monostable VCO Schmitt problem.asc". The simulation works when a INV is used, but has problems when a SCHMITT inverter is used instead. Both use default values, and as far as I can tell they are identical other than the SCHMITT is about 4 usec more delay. The SCHMITT has no visible hysteresis when driven from a sine source.

V2 on the far left is the VCO control voltage. Up top there is a choice between INV A1 and SCHMITT A2. As long as INV A1 is in the circuit it oscillates with V2 as low as 0 volt. But if A1 is disconnected and SCHMITT A2 connected in its place the circuit does not oscillate when V2 is below 1 volt. The falling ramp from opamp U2 appears to get too small to cross an assumed lower trip point, yet there doesn't seem to be any difference between trip points; I have not changed Vt and Vh from the SCHMITT default values (not sure how).

I am trying to replicate the Schmitt action of the trigger input of a 74HC221 monostable with the LTC6993-1 and the INV along with Q1. R10 and R11 are there to divide the opamp U2 output by 5 to switch at the A1 A2 threshold of 0.5 volt when U2 is 2.5 volt.

Can anyone explain why the difference between INV and SCHMITT? Maybe I do need to set a value of 0 for Vh. Also tried SCHMTINV (A3), it has the same problem

Thanks in advance.

Hello,

I just tried your example.

Right-mouse-click on the Schmitt-inverter.

SpiceLine: Vt=0.5 Vh=0.1m

I remember a case where I additionally needed a small delay.

SpiceLine: Vt=0.5 Vh=0.1m Td=10n


Best regards,
Helmut

--- In LTspice@..., "analogspiceman" <analogspiceman@...> wrote:

--- In LTspice@..., "zeeglen" <glen@> wrote:

Can anyone explain why the difference between INV and SCHMITT?

Try reading the Help file next time before spamming the group with
your needlessly ignorant drivel. Quoting Help:

Actually, the Help file was the first place I went hunting and found this:

The Schmitt trigger devices have similar output characteristics as
the gates. Their trip points are specified with instance parameters
Vt and Vh. The low trip point is Vt-Vh and the high trip point is
Vt+Vh.

At that point I searched for "instance parameters", and one of the several pages I investigated was titled "Adding Attributes". That led to "General Attribute Editor" which displays a "Component Attribute Editor". Nowhere does it state what is meant by "Spiceline" or "Spiceline2".

That is when, as I described, I tried driving both INV and SCHMITT from the same sine wave voltage source and noted their switching voltage was identical. If so, why the difference in the circuit? That was my question.

I have since found more information online that actually clearly states how to input instance parameters using the Spiceline in the Component Attribute Editor. Too bad this information is not easily found in the Help file. Do not assume that those who come to this forum seeking assistance have not already attempted to find the answer. The reason they come to this forum is that have tried but not been able to find the answer.

--- In LTspice@..., Jim Thompson "jtanalog" wrote:

Is there any way, in a LTspice plot, to _display_ the average
of a waveform over a specified interval? Something like the
AVGX mechanism in PSpice's Probe?

Mike Engelhardt has stated that he is philosophically opposed to
such imprecise functions. What is average? Is it an analog low
pass filter function or a numerical sliding average? What order
is it and what is its corner frequency/period? Is it a fixed
percentage of the total simulation run time or perhaps some
percentage the time interval as currently displayed within the
Waveform viewer (thus changing every time the zoom level is
changed)?

Average and Integrate would be very useful visualization tools for
to help analyze data after a simulation completes (right now, if
you don't plan ahead, you must rerun after adding those functions
within the schematic), but in order to be acceptable to Mike, they
would have to be much more precisely defined (perhaps via multiple,
optional parameters) than the Pspice versions.

The LTspice waveform viewer does not currently offer a "running
average" function (it only makes available a single numeric average
for the entire data set displayed in the currently visible window).
I don't see any technical reason why the waveform viewer shouldn't
be able to generate a running average, but Mike Engelhardt seems
to think that an auto adjusting running average would be too ill
defined (dependent on window span and an arbitrary averaging
function) and therefore misleading or at best a poor general
purpose compromise to what is actually needed in a vast variety
of individual circumstances (personally, I think that Mike may
be overlooking that the value of a running average would be
more qualitative than quantitative - it would be primarily a
visualization aid).

If you really must have a running average, you could always add
into the simulation a simple low pass circuit to the signal of
interest to calculate a running average of the appropriate time
constant for your visualization needs. You would then click on
the LP output to see the running average in the waveform viewer
(of course, this requires you to set it up ahead of time or to go
back, add the LP and rerun the simulation - not very user friendly).

As a compromise, perhaps Mike could be persuaded to add the ability
to the waveform viewer (via a new waveform math function) to access
"time delayed" data points (along with the delta delay time value)
by a specified number of samples or, alternatively, access time
delayed data by a specified delay time. Then the user could make
up his own customized running average function using waveform math.

Waveform math already includes a derivative function, d(). If Mike
were to add an integrate function, something like s(x[,ic[,a]])
defined as integrate x, optional initial condition ic, reset if a
is true, then you could define a user function to build your own
"boxcar" style running average (using the built-in variable "time"
and the modulus function operator "%").

--- In LTspice@..., "jtanalog" <ltlist@...> wrote:

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

--- In LTspice@..., "jtanalog" <ltlist@> wrote:

Is there any way, in a LTspice plot, to _display_ the average of a waveform over a specified interval? Something like the AVGX mechanism in PSpice's Probe?

-Jim Thompson

Hello Jim.

Unfortunately it's not possible to directly define a formula
with integration in the waveform viewer. One has to make a
Bv-source in the schematic or netlist.

.param d=100u
.func avgx(x,d) {(idt(x)-delay(idt(x),d))/d}

BV1 avgout 0 V=avgx(V(out),d)

BV2 avg37 0 V=avgx(V(37),d)

By the way you don't need a Bv-symbol. You could directly add
these SPICE-lines from above to your schematic. You will need
one B-device SPICE-line for every item you want to average.

I tried an example and found it's necessary to define a small
max time step in .TRAN and to switch off data compression for
best results.

.options plotwinsize=0 ; data compression off

The text after ';' is only comment.

Best regards,
Helmut

Thanks, Helmut! That's what I was looking for.

Is it possible to define your own set of functions (maybe in a library somewhere) that can be used later?

(I still haven't found the VDMOS tool. Can you give me a link?)

-Jim Thompson

Hello Jim,

Only plot-formulas could be in a central file managed by LTspice,
but this is dangerous when you over-install LTspice intentionally
or by accident or when you move to another PC and have forgotten
it.You could have your functions in your own file and .lib it to
your schematic.

The VDMOS-tools you asked for is in the folder Software.

Files > Util > Files > Util > Model Tools > Board Level MOSFET (VDmos)> Software




Another program is this one.

Files > Util > vdmos171.zip




Both programs will still require hand tuning.

Best regards,
Helmut

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

--- In LTspice@..., "jtanalog" <ltlist@> wrote:

Is there any way, in a LTspice plot, to _display_ the average of a waveform over a specified interval? Something like the AVGX mechanism in PSpice's Probe?

-Jim Thompson

Hello Jim.

Unfortunately it's not possible to directly define a formula
with integration in the waveform viewer. One has to make a
Bv-source in the schematic or netlist.

.param d=100u
.func avgx(x,d) {(idt(x)-delay(idt(x),d))/d}

BV1 avgout 0 V=avgx(V(out),d)

BV2 avg37 0 V=avgx(V(37),d)

By the way you don't need a Bv-symbol. You could directly add
these SPICE-lines from above to your schematic. You will need
one B-device SPICE-line for every item you want to average.

I tried an example and found it's necessary to define a small
max time step in .TRAN and to switch off data compression for
best results.

.options plotwinsize=0 ; data compression off

The text after ';' is only comment.

Best regards,
Helmut

Thanks, Helmut! That's what I was looking for.

Is it possible to define your own set of functions (maybe in a library somewhere) that can be used later?

(I still haven't found the VDMOS tool. Can you give me a link?)

-Jim Thompson

--- In LTspice@..., "zeeglen" <glen@...> wrote:

Can anyone explain why the difference between INV and SCHMITT?

Try reading the Help file next time before spamming the group with
your needlessly ignorant drivel. Quoting Help:
________________________________________________________

The gates default to 0V/1V logic with a logic threshold of .5V,
no propagation delay, and a 1Ohm output impedance. Output
characteristics are set with these instance parameters:

Name Default Description
------------------------------
Vhigh |. 1 .| Logic high level
Vlow .|. 0 .| Logic low level
Trise |. 0 .| Rise time
Tfall |Trise| Fall time
Tau . |. 0 .| Output RC time constant
Cout .|. 0 .| Output capacitance
Rout .|. 1 .| Output impedance
Rhigh |Rout | Logic high level impedance
Rlow .|Rout | Logic low level impedance

Note that not all parameters can be specified on the same instance
at the same time, e.g., the output characteristics are either a
slewing rise time or an RC time constant, not both.

The propagation delay defaults to zero and is set with instance
parameter Td. Input hold time is equal to the propagation delay.

The input logic threshold defaults to .5*(Vhigh+Vlow) but can be
set with the instance parameter Ref. The hold time is equal to the
propagation delay.

The Schmitt trigger devices have similar output characteristics as
the gates. Their trip points are specified with instance parameters
Vt and Vh. The low trip point is Vt-Vh and the high trip point is
Vt+Vh.

The gates and Schmitt trigger devices supply no timestep information
to the simulation engine by default. That is, they don't look when
they are about to change state and make sure there's a timestep close
to either side of the state change. The instance parameter tripdt
can be set to stipulate a maximum timestep size the simulator takes
across state changes.

--- In LTspice@..., "jtanalog" <ltlist@...> wrote:

Is there any way, in a LTspice plot, to _display_ the average of a waveform over a specified interval? Something like the AVGX mechanism in PSpice's Probe?

-Jim Thompson

Hello Jim.

Unfortunately it's not possible to directly define a formula
with integration in the waveform viewer. One has to make a
Bv-source in the schematic or netlist.

.param d=100u
.func avgx(x,d) {(idt(x)-delay(idt(x),d))/d}

BV1 avgout 0 V=avgx(V(out),d)

BV2 avg37 0 V=avgx(V(37),d)

By the way you don't need a Bv-symbol. You could directly add
these SPICE-lines from above to your schematic. You will need
one B-device SPICE-line for every item you want to average.

I tried an example and found it's necessary to define a small
max time step in .TRAN and to switch off data compression for
best results.

.options plotwinsize=0 ; data compression off

The text after ';' is only comment.

Best regards,
Helmut

Hi all. I've just uploaded a file "Monostable VCO Schmitt problem.asc". The simulation works when a INV is used, but has problems when a SCHMITT inverter is used instead. Both use default values, and as far as I can tell they are identical other than the SCHMITT is about 4 usec more delay. The SCHMITT has no visible hysteresis when driven from a sine source.

V2 on the far left is the VCO control voltage. Up top there is a choice between INV A1 and SCHMITT A2. As long as INV A1 is in the circuit it oscillates with V2 as low as 0 volt. But if A1 is disconnected and SCHMITT A2 connected in its place the circuit does not oscillate when V2 is below 1 volt. The falling ramp from opamp U2 appears to get too small to cross an assumed lower trip point, yet there doesn't seem to be any difference between trip points; I have not changed Vt and Vh from the SCHMITT default values (not sure how).

I am trying to replicate the Schmitt action of the trigger input of a 74HC221 monostable with the LTC6993-1 and the INV along with Q1. R10 and R11 are there to divide the opamp U2 output by 5 to switch at the A1 A2 threshold of 0.5 volt when U2 is 2.5 volt.

Can anyone explain why the difference between INV and SCHMITT? Maybe I do need to set a value of 0 for Vh. Also tried SCHMTINV (A3), it has the same problem

Thanks in advance.

--- In LTspice@..., "jtanalog" <ltlist@...> wrote:

Is there any way, in a LTspice plot, to _display_ the average of a waveform over a specified interval? Something like the AVGX mechanism in PSpice's Probe?

-Jim Thompson

Jim,

I'm surprised you haven't looked at the LTspice help file. This is in the help under Waveform Viewer>Waveform Arithmetic.

Rick

Is there any way, in a LTspice plot, to _display_ the average of a waveform over a specified interval? Something like the AVGX mechanism in PSpice's Probe?

-Jim Thompson