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

What is the purpose of Cartesian plot? I'm sure it makes some things more convenient than a bode plot. What things?

- keantoken

Hello Keantoken,

If you're doing RF design, on oscillators, for example, it is essential to be able to see both real and imaginary parts clearly and separately without having to do mental arithmetic for each frequency displayed. The Cartesian presentation shows this much better for most people, although a few will claim they can glean everything they need from a polar plot. But then some people are able to write a complete GUI in one line of C.

For doing serious RF design, LTspice is not the ideal tool, since it does not have native Smith chart and cannot handle S-parameters, but it is at least possible.

Regards,
Tony

--- In LTspice@..., "stm6823@..." <stevemorris@...> wrote:

Tony,
Thanks for answering. I thought FILES&#92;AD8336 in my help request would indicate where all the files were. Is there another way I should have done it?
STM

--- In LTspice@..., "Tony Casey" <tony@> wrote:

--- In LTspice@..., "stm6823@" <stevemorris@> wrote:

When I try to run AD8336-2.asc in FILES&#92;AD8336 I get an error message that contains "Circuit: * C:&#92;Program Files&#92;LTC&#92;AD models&#92;AD8336&#92;AD8336-2.asc

WARNING: Node U1:U4_N24227 is floating."
But checking the .net file I do not find any NC.
Whats wrong?
Thanks in advance,
STM

Hello Steve,

Apologies for the earlier comment. I found your files in Files>Temp>AD8336, but there was no announcement or indication from you that they were there.

You schematic wouldn't run, but not due to the reason you gave. You had hard-coded the absolute path of the model file into the symbol, and of course when it is downloaded by someone else, it will, in general, not have the same path that you used. If you put the .included file into the .asc directory, you don't need any absolute path, as LTspice will always look there.

The error I got was "timestep too small... etc", which sometimes means the model is dodgy, but the schematic is probably at least syntactically OK.

I changed your schematic to something resembling the ADI application circuit, but still got a convergence error with an .op analysis, so I think the model file is the problem, but I'm afraid I don't have the time or inclination to debug it. Sorry.

Regards,
Tony

Hello STM,

It's possible I looked before the files were actually there, but when I found them they were in Files>Temp>AD8336, not Files>AD8336.

It's also helpful when uploading files, to check the box about making an announcement to the group with a comment, not least because that message will have the correct hyperlink to the uploaded file because it's autogenerated and not prone to user error.

I'm glad Helmut sorted you out, though, as he usually does when others fail.

Regards,
Tony

Indeed, and that is the reason why I just use the datasheet and the universalopamp symbol to get rid of the problems. Most times the universalopamp makes a better job.

- Henry

--
ehydra.dyndns.info

RobertTalty schrieb:

Tony,
Thanks for answering. I thought FILES&#92;AD8336 in my help request would indicate where all the files were. Is there another way I should have done it?
STM

Could someone let me know where I can find spice models for both 1N5811 and 1N6618? I was unable to locate them in the on-line library.

Thanks,

Dan

Could someone let me know where I can find spice models for both 1N5811 and 1N6618?
?
Thanks,
?
Dan

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

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

--- In LTspice@..., "rug_rossi" <rrossi@> wrote:

I need to add a noise generator to the model of a sensor
(simply a behavioral source), in order to perform some
noise analysis.

Noise is described by a noise density and a 1/f corner.

which is the best way to do that?
Add to my model a voltage follower made with the
Universal OP amp level 1, or there is a better way?

best regards,

Ruggero Rossi

Hello Ruggero,

The 1/f noise is implemented in diodes. Thus diode noise may be
the natural choice for an 1/f noise source.

Files > Tut > noisegen
Files > Tut > noisegen_with_subcircuits
Files > Tut > new_diode_noise.asc


You already mentioned the "universalopamp". It contains
parameters en and enk to set noise value and corner frequency.

Best regards,
Helmut

Thank you,

noisegen.asc + noisegen.asy is what I needed!

Ruggero

What is the purpose of Cartesian plot? I'm sure it makes some things more convenient than a bode plot. What things?

- keantoken

Dear Helmut,
?
Thank you very much for your quick response.
Yes, I was doing .AC simulation.
?
Sincerely,
?
Mahmudul Kabir, Japan?


--- In LTspice@..., Mahmudul Kabir <nilonjana@...> wrote:

Dear Members,
?
Is there any chance to calculate of real or imaginary part
of impedance while doing a simulation?with any AC voltage?
?
Or is it possible to draw?a trace of real part or imaginary
part of impedace in LTspice?
?
Thank you in advance,
?
Mahmudul Kabir, Japan

Hello Mahmudul Kabir,

I assume you use .AC simulation. In this case you can plot
in Cartesian format which shows the real part with a solid
line and the imaginary part with a dashed line.

Best regards,
Helmut




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

In message <j4sde1+lkfq@...>, dated Thu, 15 Sep 2011, cukkacan <mustafa_cukka@...> writes:

Hey, i am sophomore at the university, and i have a circuit sketch and data sheet. However, i dont know how to use LT Spice effectively. i couldnt build the circuit on LT Spice perfectly. Could you help me about this issue ?

Study the examples and tutorials available on the list's web site. Read the Help. Upload your non-working schematic to the web site Files -> Temp and tell us you've done it.

Also, advices about Class D amp are welcome. i need a working class-d amp circuit about 10-20W.i have checked on the web, topics are not live.

This list is not a general design help list. A web search for 'Class D' will provide you with hundreds of good hits (and some bad ones, but you can't win them all).
--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
When I point to a star, please look at the star, not my finger. The star will
be more interesting.

--- In LTspice@..., Mahmudul Kabir <nilonjana@...> wrote:

Dear Members,
?
Is there any chance to calculate of real or imaginary part
of impedance while doing a simulation?with any AC voltage?
?
Or is it possible to draw?a trace of real part or imaginary
part of impedace in LTspice?
?
Thank you in advance,
?
Mahmudul Kabir, Japan

Hello Mahmudul Kabir,

I assume you use .AC simulation. In this case you can plot
in Cartesian format which shows the real part with a solid
line and the imaginary part with a dashed line.

Best regards,
Helmut

--- In LTspice@..., "rug_rossi" <rrossi@...> wrote:

I need to add a noise generator to the model of a sensor
(simply a behavioral source), in order to perform some
noise analysis.

Noise is described by a noise density and a 1/f corner.

which is the best way to do that?
Add to my model a voltage follower made with the
Universal OP amp level 1, or there is a better way?

best regards,

Ruggero Rossi

Hello Ruggero,

The 1/f noise is implemented in diodes. Thus diode noise may be
the natural choice for an 1/f noise source.

Files > Tut > noisegen
Files > Tut > noisegen_with_subcircuits
Files > Tut > new_diode_noise.asc


You already mentioned the "universalopamp". It contains
parameters en and enk to set noise value and corner frequency.

Best regards,
Helmut

Dear Members,
?
Is there any chance to calculate of real or imaginary part of impedance while doing a simulation?with any AC voltage?
?
Or is it possible to draw?a trace of real part or imaginary part of impedace in LTspice?
?
Thank you in advance,
?
Mahmudul Kabir, Japan
?

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

--- In LTspice@..., "stm6823@..." <stevemorris@...> wrote:

When I try to run AD8336-2.asc in FILES&#92;AD8336 I get an error message that contains "Circuit: * C:&#92;Program Files&#92;LTC&#92;AD models&#92;AD8336&#92;AD8336-2.asc

WARNING: Node U1:U4_N24227 is floating."
But checking the .net file I do not find any NC.
Whats wrong?
Thanks in advance,
STM

Hello STM,

I have corrected your symbol and the schematic. It has been
also necessary to add some convergence help.
It has required the critical option

.options cshunt=1e-15

I have uploaded a working example.

Files > Temp > AD8336 > AD8336_1.zip.

Best regards,
Helmut

I need to add a noise generator to the model of a sensor (simply a behavioral source), in order to perform some noise analysis.

Noise is described by a noise density and a 1/f corner.

which is the best way to do that?
Add to my model a voltage follower made with the Universal OP amp level 1, or there is a better way?

best regards,

Ruggero Rossi

Hey, i am sophomore at the university, and i have a circuit sketch and data sheet. However, i dont know how to use LT Spice effectively. i couldnt build the circuit on LT Spice perfectly. Could you help me about this issue ?

Also, advices about Class D amp are welcome. i need a working class-d amp circuit about 10-20W.i have checked on the web, topics are not live.

--- In LTspice@..., "pindsen" <windven@...> wrote:

Hi,

I need an BSS138 in my LTSpice simulation.
Since I can't find that component in the program itself, I need to make it.

I have done the following steps but LTspice won't simulate:

1) Downloaded a Zetex BSS138 spice subcircuit and placed it in a "BSS138.sub" file
2) The spice file is placed in c:&#92;program files&#92;LTC&#92;LTspiceIV&#92;lib&#92;sub
3) Included a nmos symbol (nmos.asy) in the design
4) Renamed the symbol to BSS138/ZTX
5) Add a spice directive command ".inc BSS138.sub"
6) Hit the run button
7) LTspice can't simulate and says "Can't find definition of model "bss138".

The Zetex spice model can be seen here:

*ZETEX BSS138 Spice Mosfet Subcircuit Last revision 11/91
*
.SUBCKT BSS138/ZTX 3 4 5
* Nodes D G S
M1 3 2 5 5 MOD1
RG 4 2 343
RL 3 5 6E6
D1 5 3 DIODE1
.MODEL MOD1 NMOS VTO=1.109 RS=1.474 RD=1.59 IS=1E-15 KP=0.597
+CGSO=23.5P CGDO=4.5P CBD=53.5P PB=1 LAMBDA=267E-6
.MODEL DIODE1 D IS=1.254E-13 N=1.0207 RS=0.222
.ENDS

Can anyone help?

Best regards
Carsten Wind
Denmark

Hello Carsten,

4a)
Ctrl-right-mouse-click on the placed symbol nmos.
Change Prefix:MN to Prefix:X

2) I always recommend to save model files in the folder of the
schematic.

Best regards,
Helmut

Hi,

I need an BSS138 in my LTSpice simulation.
Since I can't find that component in the program itself, I need to make it.

I have done the following steps but LTspice won't simulate:

1) Downloaded a Zetex BSS138 spice subcircuit and placed it in a "BSS138.sub" file
2) The spice file is placed in c:&#92;program files&#92;LTC&#92;LTspiceIV&#92;lib&#92;sub
3) Included a nmos symbol (nmos.asy) in the design
4) Renamed the symbol to BSS138/ZTX
5) Add a spice directive command ".inc BSS138.sub"
6) Hit the run button
7) LTspice can't simulate and says "Can't find definition of model "bss138".

The Zetex spice model can be seen here:

*ZETEX BSS138 Spice Mosfet Subcircuit Last revision 11/91
*
.SUBCKT BSS138/ZTX 3 4 5
* Nodes D G S
M1 3 2 5 5 MOD1
RG 4 2 343
RL 3 5 6E6
D1 5 3 DIODE1
.MODEL MOD1 NMOS VTO=1.109 RS=1.474 RD=1.59 IS=1E-15 KP=0.597
+CGSO=23.5P CGDO=4.5P CBD=53.5P PB=1 LAMBDA=267E-6
.MODEL DIODE1 D IS=1.254E-13 N=1.0207 RS=0.222
.ENDS

Can anyone help?

Best regards
Carsten Wind
Denmark

Dear Sir,
Will you please tell us how to do it? There might be cases when it is not such a bad idea.
Best Regards
E.A.Neonakis

--- In LTspice@..., "Tony Casey" <tony@...> wrote:

Incidentally, the registry hack method works for almost any kind of file association, and can usefully be employed to invoke the a native Linux PDF reader, for example, from within many Windows applications (running in wine) that can call PDF files, instead of using a Windows version installed in the same wine bottle.

Thanks for that, although I use the Linux version of the Adobe reader for viewing PDFs. and LTspice is now the only Windows app that I use on a regular basis.

However, I'd like to try it on .net, .cir and .log files - I don't like the appearance of Notepad (purely a personal thing) so I'll try setting up an association to use the native editor of my choice.

Cheers,

Martin