Interesting -- seyedabrishami.se who asked this question has already left the group.

jessemccree1701 wrote, "Is there anywhere I could find a 74AC821, or any 10 bit d flip flop spice model ..."

Please note, what you are looking for is the SPICE model for a D flip-flop.? People don't make (or rarely ever make) SPICE models of something that is repeated 10 times; they make SPICE models for one of them.? Then you just add 10 of them to your schematic.? SPICE models don't care about pin numbers or how many are on the same die.

So what exactly are you looking for?? ANY D-flop?? Or only one from the 74AC family?? Are other families (such as 74ACT, 74HC, etc.) close enough?? I don't want to suggest that any of these are easy to find -- I just want to narrow down what you need.

If all you want is "any" D-flop, there is the basic "dflop" that comes with LTspice.? It's in the [Digital] folder.? If that one meets your needs, being a generic D-flop that you can replicate 10 times, read the Help page for A-devices (LTspice > Circuit Elements > A. Special Functions).? You should add at least the parameters Vhigh and Td.? Ask if you need help with that.

Andy

Hi, sorry if this is not the right place to put this, but after around 4 hours of searching, I am out of ideas

?

Is there anywhere I could find a 74AC821, or any 10 bit d flip flop spice model, I have been unable to find one

?

Thanks in advance

Kerim wrote:

? ? "But being a programmer, I was just curious about the hidden phantom code in the program (LTspice IV) that?insists to also generate these added edges and give them?different rise and fall times."

We could give you an explanation (those details are starting to come back to me) -- but it might be best to ignore why it happens.? I think it's best considered a "bug".

I'm pretty sure it affects only the visual display in the waveform plot window, so doesn't affect the measured rise and fall times (unless you only eyeball them).

Andy

Did you review the content of the file

which documents (as much as there is) these files?

As a brushless DC motor, the speed should be [nearly] proportional to
the applied voltage and the commutation frequency should proportional to
the speed.

Donald.

*Plain Text* email -- it's an accessibility issue
() no proprietary attachments; no html mail
/\ <>

Hello Jayal

I am have intermediate skill for simulation, just trying to simulation BLDC
motor from LTwiki example(
http://ltwiki.org/files/LTspiceIV/examples/Motors\MotorTest01). I managed to
simulation with default parameters but not sure, if I can change speed or
commutation frequency.

The speed of the simulation is given (mostly) by the models. As for
the parameters, they are there, as long as you know what you're
changing, nobody is stopping you from testing.

--
Vlad
______________________
ltspicegoodies.ltwiki.org v2:
quite universal analog/digital filter,
power electronics, signal processing,
easy to work with math functions,
digital models, and rants.

Hello Kerim

I remember this from LTspice IV days, but it never bothered me. I
suppose it posed no interest at the time, and in time I just learned
to accept it. I guess I'm a believer now.

Thanks, I thought it might be just me.
After all, this is not important because the added inclined edges don't pose
a problem, speaking practically.

But being a programmer, I was just curious about the hidden phantom code in
the program (LTspice IV) that insists to also generate these added edges and
give them different rise and fall times.

I was referring to the duplicate traces when using the '@'. Those
edges are because of the waveform compression, as mentioned before in
the thread.

--
Vlad
______________________
ltspicegoodies.ltwiki.org v2:
quite universal analog/digital filter,
power electronics, signal processing,
easy to work with math functions,
digital models, and rants.

Hi,

I am have intermediate skill for simulation, just trying to simulation BLDC motor from LTwiki example(http://ltwiki.org/files/LTspiceIV/examples/Motors\MotorTest01). I managed to simulation with default parameters but not sure, if I can change speed or commutation frequency.?

Your comments would be appreciated.?

Thanks,
Jayal Pansuriya

On 23/02/2021 20:47, Andy I wrote:

If it's for simulation, you can probably use the UniversalOpamp2.

It depends on what "High-power" means. The UniversalOpamp2 has an additional limit to output current (over and above that set by "ilimit") set by the on resistance of the O/P devices being 10Ω in the model, if I remember correctly. If these are edited to something lower, the current capability can be increased. I have saved a special version of UniversalOpamp2 just for such uses.

--
Regards,
Tony

On Tue, Feb 23, 2021 at 11:26 PM, Vlad wrote:

I remember this from LTspice IV days, but it never bothered me. I
suppose it posed no interest at the time, and in time I just learned
to accept it. I guess I'm a believer now.

Thanks, I thought it might be just me.
After all,?this is not important because the added inclined edges don't pose a problem, speaking practically.

But being a programmer, I was just curious about the hidden phantom code in the program (LTspice IV) that?insists to also generate these added edges and give them?different rise and fall times.

Kerim

Hello Tony

For better or worse, it looks like plotting waveforms with @1 or @2
doesn't work right, but selecting them from the View > Select Steps
menu does. Changing the plotwinsize option to make the timesteps
smaller helps minimize the appearance of the problem, but it does not
actually fix it.

It's strange, I use the @1, @2, etc. notation all the time and I very
rarely see artefacts. It's essential when you need to use this feature
in waveform arithmetic.

I remember this from LTspice IV days, but it never bothered me. I
suppose it posed no interest at the time, and in time I just learned
to accept it. I guess I'm a believer now.

--
Vlad
______________________
ltspicegoodies.ltwiki.org v2:
quite universal analog/digital filter,
power electronics, signal processing,
easy to work with math functions,
digital models, and rants.

Hello Andy

Thanks. I remember experimenting with it to see if they were also affected,
but that was a long time ago.

Well I had forgotten about flat(), but seeing it triggered the right memory.

--
Vlad
______________________
ltspicegoodies.ltwiki.org v2:
quite universal analog/digital filter,
power electronics, signal processing,
easy to work with math functions,
digital models, and rants.

If it's for simulation, you can probably use the UniversalOpamp2.

Andy

开云体育

Check APEX Microtechnology. They make several that meet those requirements and have simulation models for most.

Dave

Hi,

I am looking for an Op-amp with these descriptions.?

I would really appreciate it if you help me find a proper model.

200 V
3~30KHz

-- 
David A. Wayne                                                AA7DW
Desert Microtechnology Associates, Inc. ? IC Design and Technology
16611 N. 91st Street, Suite 103             Analog and Mixed-Signal
Scottsdale, AZ  85260  USA                    CMOS, Bipolar, BiCMOS
Ph: 480-515-0005 x101         Cell: 602-793-4440

Hi,

I am looking for an Op-amp with these descriptions.?

I would really appreciate it if you help me find a proper model.

200 V
3~30KHz

Here is one more suggestion, which I'm putting here because it might help everyone.

In Grroups.io, when you see a button to "Leave Group", it means to permanently leave the group = unsubscribe from the group.? Do not click that button unless you really want to unsubscribe from the group.

If you are done for the moment and want to move on to something else, that is NOT the button to click.? You don't need to click anything.

Andy

Tony,?

I agree.

Shame that the current On-Semi data does not provide an I-V plane plot.?

All that said, however, a circle back to small signal data set is still useful and unfortunate in many cases
that will require further measurements.?

开云体育

On 23/02/2021 15:44, alan victor wrote:

While many devices do not have S, they do have other parameter sets, h or y, ?and that requires conversion to S. Finally direct measure of S may be required.?For the case of the 3904, either measure the S directly or use h parameters and convert to S. Some y parameters exist for the 3904 as well and the same process, conversion to S is required. At that point, ?with an available non linear model, the comparison to measured as well converted to S data is needed before one can trust a non linear model.?

Instances exist where no model is available, either linear or non linear. Then measured data is required. Stated previously, beginning with S measured data does provide a gateway to a reasonable first pass approach to a non linear design.

I admire your dedication to S-parameters, but I can't help thinking going via Y-parameters (which are rarely given in modern datasheets) is more work than deriving from scratch a half-decent SPICE model directly from the datasheet. For example, the current On-Semi (was Fairchild) 2N3904 provides almost everything needed except an Ic vs. Vce plot. It even has some H-parameter graphs, but unfortunately magnitude only at 1kHz (except Hfe) , so not that useful.

-- 
Regards,
Tony

Andy,

I'll be glad to share data.

As my time permits I will search for what I have and post. This was done quite some time ago.

Many of the files are on a HP Winchester CS 80? drive which was connected to a workstation and analyzer. So recovery and assembly?
of the data takes some doing.

Have a great day.?