Re: Need help with 74LVC1G74 parameters
On Mon, Dec 30, 2024 at 07:03 PM, Jim McLucas wrote:
* - VCC={VCC} Speed=1 Tripdt=100p
,,,
Do I use Speed=1 for 5V operation? What do I use for Tripdt value? What does Tripdt=100p mean?
Here is the way these three parameters are most commonly used in these (and similar) models:
- Speed allows you to choose a relative speed variation. Speed=1 is for a nominal (typical) part. It is independent of VCC. You might try values such as Speed=0.7 or Speed=1.5, for slow or fast parts.
- VCC is the power supply voltage. With luck, the model already changes its speed depending on the value of VCC, independently of the Speed parameter.
- The Tripdt parameter is a helpful convergence aid for some of the internal devices inside the model. It suggests to LTspice that it should throttle the internal timestep to 100 ps or less when the signal is changing. This helps prevent LTspice from advancing right through a change of state (low to high or high to low). It's unlikely that you would need to change that parameter.
Andy
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Re: Need help with 74LVC1G74 parameters
Oops, I meant to say "74LVC1G74.
Jim
|
Need help with 74LVC1G74 parameters
I need help setting up the 74LVC1g74 Flipflop parameters for 5V operation.
From the 74LVC1G.lib file I get the following information:
_________________________________________________________________________________________________________
* Delays have been adjusted for Vcc = 1V8/2V7/3V3/5V (LVC) using the test conditions stated in the * Nexperia data sheets, and generally achieve Tpd errors less than 10%. The actual VCC voltage needs * to be passed to each device as a parameter, either a fixed value, or a variable by placing: * * - VCC={VCC} Speed=1 Tripdt=100p * * in the Value field of the symbol, where {VCC} denotes that it is defined somewhere in the schematic. * * Temperature effects are currently not modelled. * * https://www.nexperia.com/products/analog-logic-ics/family/LVC/#/p=1,s=0,f=,c=,rpp=,fs=0,sc=,so=,es=______________________________________________________________________________________________________________
Do I use Speed=1 for 5V operation? What do I use for Tripdt value? What does Tripdt=100p mean?
Your help will be much appreciated.
Thanks,
Jim
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Re: Can LTspice show Cross Over distortion of a class B type amplifiers...
In order to tune crossover distortion, the best is visualizing
linearity. Distortion percentage doesn't indicate what to adjust.
Le 30/12/2024 à 16:46, aledelaplaza via
groups.io a écrit :
переключити цитоване повідомлення
Показати цитований текст
To evaluate
and quantize crossover distortion you can use a notch filter
(RC bridge) to eliminate the fundamental frequency out of the
output voltage.
I have uploaded an example schematic
featuring the Quad 303 output stage.
--
Regards,
Tony
On 30/12/2024 11:56, Tony Casey wrote:
You can also do this with a .DC
analysis. With this it's also very easy to do a
"wingspread" plot, which plots the incremental gain, which
is very revealing.
--
Regards,
Tony
On 30/12/2024 11:43, John Woodgate wrote:
1.Use.TRAN analysis, not .AC,
because that doesn't show non-linearity.
2. Check that the current through
the output devices is very small with no input
signal.
On 2024-12-30 10:36, dlwarr911 via groups.io wrote:
If I build a Class B amplifier (all have cross
over distortion) What do I have to do, to see cross
over in a trace...
All I get is a perfect looking sign wave... What
would be the analysis and steps to do this...??
Any thoughts on this would certainly be
appreciated..... Thanks....
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
Re: LM324 based automatic voltage stabilizer circuit simulation
On Mon, Dec 30, 2024 at 11:44 AM, MD MUBDIUL HASAN wrote:
kindly share the uploaded link here.
It's in here:
Files > Temp
which is where all newly uploaded files are.
Andy
|
Re: LM324 based automatic voltage stabilizer circuit simulation
Mike,
Thanks a lot, kindly share the uploaded link here.
On Monday, December 30, 2024 at 10:48:06 AM GMT+1, Mike Fraser <mrfraser@...> wrote:
Dave,
I just uploaded the file "MF_VCpot.zip".
I got tired of trying to allocate floating net names to different pots.
I chose the pin name as "PC", because it is the Pot Control pin.
Feel free to Look over the files and see if it will help with your "Fz" issue.
I think that it is easy to apply net names from the top level to subcircuits.
Mike
|
Re: Can LTspice show Cross Over distortion of a class B type amplifiers...
Yes, I know. I have already uploaded such a schematic
example using one a few years go. It doesn't explicitly show
crossover distortion, though - just the residual.
--
Regards,
Tony
On 30/12/2024 16:46, aledelaplaza via
groups.io wrote:
To evaluate
and quantize crossover distortion you can use a notch filter
(RC bridge) to eliminate the fundamental frequency out of the
output voltage.
I have uploaded an example schematic
featuring the Quad 303 output stage.
--
Regards,
Tony
On 30/12/2024 11:56, Tony Casey wrote:
You can also do this with a .DC
analysis. With this it's also very easy to do a
"wingspread" plot, which plots the incremental gain, which
is very revealing.
--
Regards,
Tony
On 30/12/2024 11:43, John Woodgate wrote:
1.Use.TRAN analysis, not .AC,
because that doesn't show non-linearity.
2. Check that the current through
the output devices is very small with no input
signal.
On 2024-12-30 10:36, dlwarr911 via groups.io wrote:
If I build a Class B amplifier (all have cross
over distortion) What do I have to do, to see cross
over in a trace...
All I get is a perfect looking sign wave... What
would be the analysis and steps to do this...??
Any thoughts on this would certainly be
appreciated..... Thanks....
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
Re: Can LTspice show Cross Over distortion of a class B type amplifiers...
To evaluate and quantize crossover distortion you can use a notch filter (RC bridge) to eliminate the fundamental frequency out of the output voltage.
I have uploaded an example
schematic featuring the Quad 303 output stage.
--
Regards,
Tony
On 30/12/2024 11:56, Tony Casey wrote:
You
can also do this with a .DC analysis. With this it's also very
easy to do a "wingspread" plot, which plots the incremental gain,
which is very revealing.
--
Regards,
Tony
On 30/12/2024 11:43, John Woodgate
wrote:
1.Use.TRAN analysis, not .AC, because that
doesn't show non-linearity.
2. Check that the current through the
output devices is very small with no input signal.
On 2024-12-30 10:36, dlwarr911 via
groups.io wrote:
If I build a Class B amplifier (all have cross over
distortion) What do I have to do, to see cross over in a
trace...
All I get is a perfect looking sign wave... What would be
the analysis and steps to do this...??
Any thoughts on this would certainly be appreciated.....
Thanks....
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
Re: LTspice 24.1 Beta Available Now
On Mon, Dec 30, 2024 at 09:49 AM, <emilien.sabard@...> wrote:
- MultiTabs per plot setting could be very nice, especially when we changed simulation between .ac and .tran we do not necessarily want to draw the same curves.
The best way to handle different simulations, is to name the schematics differently. Say, MySim_Tran.asc and MySim_AC.asc, which might be identical except for their simulation commands. Then each has its own plot settings file, and you can switch back and forth without difficulty. Also this lets you keep both results available for later, since each .RAW file can contain one but not both simulations.
- For hierarchical schemas: Option to automatically update the port between the schema (.asc) and the symbol (.sym)
What is there that you can't already do? I am just trying to understand the thought.
In many cases, an automatically created symbol file from the lower-level schematic is sufficient. Therefore, just delete the old symbol file and ;let LTspice make a new one.
LTspice does not use ".sym" files. I'm assuming you meant to write ".asy".
Andy
|
Re: LTspice 24.1 Beta Available Now
On Mon, Dec 30, 2024 at 09:49 AM, <emilien.sabard@...> wrote:
Some additionals features : Some options for future releases. Christmas is over, but it will be for next year:)
...
As you know, this group is not the place to officially make suggestions to the LTspice developers about recommendations or improvements. This group is people like you who use LTspice; we are not its developers. To make your recommendations known to Analog Devices, you must follow what it says under Help > About LTspice and use the EngineerZone.
Andy
|
Re: LTspice 24.1 Beta Available Now
Hello,
Some additionals features : Some options for future releases. Christmas is over, but it will be for next year:)
- MultiTabs per plot setting could be very nice, especially when we changed simulation between .ac and .tran we do not necessarily want to draw the same curves.
- For hierarchical schemas: Option to automatically update the port between the schema (.asc) and the symbol (.sym)
Emilien
|
The following items have been added to the Files area of the LTspice@groups.io group.
By: Tony Casey <tony@...>
Description:
Crossover distortion testjig. Uses the Quad 303 O/P stage as an example.
Includes "Wingspread" and non-linearity vs. quiescent current plots.
|
Re: Can LTspice show Cross Over distortion of a class B type amplifiers...
переключити цитоване повідомлення
Показати цитований текст
You
can also do this with a .DC analysis. With this it's also very
easy to do a "wingspread" plot, which plots the incremental gain,
which is very revealing.
--
Regards,
Tony
On 30/12/2024 11:43, John Woodgate
wrote:
1.Use.TRAN analysis, not .AC, because that
doesn't show non-linearity.
2. Check that the current through the
output devices is very small with no input signal.
On 2024-12-30 10:36, dlwarr911 via
groups.io wrote:
If I build a Class B amplifier (all have cross over
distortion) What do I have to do, to see cross over in a
trace...
All I get is a perfect looking sign wave... What would be
the analysis and steps to do this...??
Any thoughts on this would certainly be appreciated.....
Thanks....
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
Re: Can LTspice show Cross Over distortion of a class B type amplifiers...
If your amp is in a high gain negative feedback loop, it can be harder to see the crossover distortion because the feedback look "eliminates" most of it. Getting rid of that feedback would make it easier to see. Higher frequencies might show it more because there is less open-loop gain.
Did you ask this question because you tried a simulation and couldn't see the distortion? Or were you just wondering whether simulations show it? Simulations do indeed show crossover distortion because they simulate what the amplifier actually does in real life with real hardware. The degree to which you can see it depends on many things - not only in simulation but in real hardware.
Andy
|
Re: Can LTspice show Cross Over distortion of a class B type amplifiers...
On Mon, Dec 30, 2024 at 05:41 AM, <dlwarr911@...> wrote:
Can LTSpice show Cross Over distortion of a class B type amplifiers...
Yes.
If I build a Class B amplifier (all have cross over distortion) What do I have to do, to see cross over in a trace...
All I get is a perfect looking sign wave... What would be the analysis and steps to do this...??
To "see" it, as a distorted- looking sinewave, you need to make the distortion bad enough so that it stands out. Visually looking at sinewaves, they generally need to be pretty bad for humans to see it with our eyes.
Use a .TRAN analysis.
It might help to disable LTspice's waveform compression (".options plotwinsize=0") so that it does not gloss over small levels of distortion that are hard to see.
You could add a .FOUR to print out the harmonic levels (in the .LOG file). Or run an FFT. They will help you see the distortion effects (as harmonic or IM distortion) even if the sinewave looks pretty good visually.
In other words, do the same thing you would do if you had an amplifier on a bench in front of you. Hooked up to a scope, you might or might not see the distortion unless you look hard. Or use the right test equipment (e.g., distortion analyzer).
You could in principle painstakingly compare the output with an undistorted sinewave, but getting its amplitude and phase just right could be challenging.
Andy
|
Re: Can LTspice show Cross Over distortion of a class B type amplifiers...
You can also do this with a .DC analysis. With this it's also very
easy to do a "wingspread" plot, which plots the incremental gain,
which is very revealing.
--
Regards,
Tony
On 30/12/2024 11:43, John Woodgate
wrote:
1.Use.TRAN analysis, not .AC, because that
doesn't show non-linearity.
2. Check that the current through the output
devices is very small with no input signal.
On 2024-12-30 10:36, dlwarr911 via
groups.io wrote:
If I build a Class B amplifier (all have cross over
distortion) What do I have to do, to see cross over in a
trace...
All I get is a perfect looking sign wave... What would be
the analysis and steps to do this...??
Any thoughts on this would certainly be appreciated.....
Thanks....
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
Re: Can LTspice show Cross Over distortion of a class B type amplifiers...
...and apply a very low input signal when running the transient
test.
Le 30/12/2024 à 11:43, John Woodgate a
écrit :
переключити цитоване повідомлення
Показати цитований текст
1.Use.TRAN analysis, not .AC, because that
doesn't show non-linearity.
2. Check that the current through the output
devices is very small with no input signal.
On 2024-12-30 10:36, dlwarr911 via
groups.io wrote:
If I build a Class B amplifier (all have cross over
distortion) What do I have to do, to see cross over in a
trace...
All I get is a perfect looking sign wave... What would be
the analysis and steps to do this...??
Any thoughts on this would certainly be appreciated.....
Thanks....
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
Re: Can LTspice show Cross Over distortion of a class B type amplifiers...
1.Use.TRAN analysis, not .AC, because that
doesn't show non-linearity.
2. Check that the current through the output
devices is very small with no input signal.
On 2024-12-30 10:36, dlwarr911 via
groups.io wrote:
If I build a Class B amplifier (all have cross over
distortion) What do I have to do, to see cross over in a
trace...
All I get is a perfect looking sign wave... What would be the
analysis and steps to do this...??
Any thoughts on this would certainly be appreciated.....
Thanks....
--
OOO - Own Opinions Only
Best Wishes
John Woodgate
Keep trying
|
Can LTspice show Cross Over distortion of a class B type amplifiers...
If I build a Class B amplifier (all have cross over distortion) What do I have to do, to see cross over in a trace...
All I get is a perfect looking sign wave... What would be the analysis and steps to do this...??
Any thoughts on this would certainly be appreciated..... Thanks....
|
Re: LM324 based automatic voltage stabilizer circuit simulation
Dave,
I just uploaded the file "MF_VCpot.zip".
I got tired of trying to allocate floating net names to different pots.
I chose the pin name as "PC", because it is the Pot Control pin.
Feel free to Look over the files and see if it will help with your "Fz" issue.
I think that it is easy to apply net names from the top level to subcircuits.
Mike
|
Tony Casey
John Woodgate