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Re: About impedance
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: 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] |
Re: Hey i am working on a Class D amp project, need help about LT Spice
John Woodgate
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. 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. |
Re: About impedance
--- In LTspice@..., Mahmudul Kabir <nilonjana@...> wrote:
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 |
Re: adding noise to the model of a sensor
--- In LTspice@..., "rug_rossi" <rrossi@...> wrote:
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 |
About impedance
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] |
Re: AD8336 failure
--- In LTspice@..., "stm6823@..." <stevemorris@...> wrote:
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 |
adding noise to the model of a sensor
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 working on a Class D amp project, need help about LT Spice
cukkacan
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. |
Re: Implementing BSS138 spice model
--- In LTspice@..., "pindsen" <windven@...> wrote:
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 |
Implementing BSS138 spice model
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:\program files\LTC\LTspiceIV\lib\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 |
Re: General SPICE environment setup
Dear Sir,
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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@..., "analogspiceman" <analogspiceman@...> wrote:
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Re: What changes would make LTspice better?
martin562284
--- 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 |
Re: General SPICE environment setup
Jim Wagner
On Sep 14, 2011, at 10:24 PM, martin562284 wrote:
I really do agree with Martin. The simple idea that one way fits all is simply not productive. Many of us have different styles of file management. The idea that our user environment must be exactly that which facilitates sharing over the internet is constraining. And, it is really at odds with the idea of giving the user many ways to hang him or her self. If we need to share a design, then why not a "share design" or "export" menu item that packages all of the needed files together and zips them in an appropriate hierarchy of folders (and adjusts directive-based model references)? The inclusion of a "project file" that references all of the project files would make file management quite straight forward. I am really quite surprised that such a strategy has not been adopted. It need not get in the way of using legacy netlists or model files. After all, virtually every software development environment allows inclusion of library files of all sorts. LTspice need not be any different! Jim Wagner Oregon Research Electronics [Non-text portions of this message have been removed] |
Re: General SPICE environment setup
martin562284
--- In LTspice@..., "analogspiceman" <analogspiceman@...> > You can more or less do this now if you know how, but it is a
really bad ideaWell, I wouldn't go so far as to say "really bad", just undesirable. But that's precisely why I'd like to have the facility to have an optional (with the emphasis on "optional") intermediate directory hierarchy - something akin to the Windows/Linux $PATH environment variable principle.... unless you are certain you will never need to shareAs I'm a one-man band, sadly I very rarely have the need/opportunity to share with others, but see below... (including with yourself when you areI regularly (almost daily) move between two or three PCs and, with the aid of Unison, have no problem in keeping all my stuff in sync. I'm not so presumptuous as to consider my designs "wonderful", but for the most part they work sufficiently well to meet my needs and I have some simple but effective, tried and tested processes for keeping track of them and the third-party models I use... To share successfully, you willMost of my projects use non-standard (ie. not provided in the standard LTspice release) models, subs or libs, not just of my own design but also third-party models, libraries and subs. I don't want to keep multiple copies of these in each project directory as it gives me a version control headache. Anything which is project-specific stays in the project directory. It's the stuff that I use time and time again that I want to find a home for, preferably separate from the LTspice lib directory, which is what my suggestion is all about. This would apply to models, also - at present LTspice has the facility to add third-party models into the standard.* files (ref. scad3.pdf, p187, para 3c) - I believe it would also be better to keep these separate. Unless Mike were toI neither expect nor need Mike to provide any such tool - I'm happy to look after that for myself. It's actually quite simple. Due to the elegance of LTspice's file formats, all the information is readily available. I'd be more than willing to assist in producing an "official" tool, should the opportunity arise. I'm not demanding nor even requesting that you or anyone else change your way of working, I'm just requesting a facility to give me, and any one else who wishes it, the freedom to work in the way we choose. In the meantime, I'm happy to share my experience with others who wish to tread the same path. |
Re: Simple model for diffin-diffout amp
Ganesan
Thanks.. I usually count on only 40 db from differential stuff or 1%
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matching.. 0.1% is achievable with a lot of attention to layout When I get time I will read his postings in detail. It reinforces my thesis that simpler models will suffice.. Why the unnecessary device level complexity..? Cheers AG On 9/14/2011 10:07 PM, RobertTalty wrote:
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Re: Simple model for diffin-diffout amp
Hi AG,
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You may want to read through a series of articles by Kendall see post# 30118 I know that he wrote a test suite for opamp models that tried to include PSRR / CMRR etc. I think this was about 2007 time frame. However everything that he is writing about is for regular single ended opamps. PSRR and CMRR in Fully differential opamps is very different to PSRR in single ended opamps. Most simulations, even with input pair mismatch, will show very very low PSRR for a fully differential opamps. The PSRR of the first stage becomes CMRR of the following stage, so if you just measure one stage fully diff out, you get almost infinite PSRR. Unfortunately the system PSRR for a fully diff system is often worse than a regular opamp (especially at low frequencies) because mismatch and asymmetry cause PSRR in fully diff opamps and this is hard to model properly. Most fully differential opamps have about 60db to 70dB PSRR that is fairly constant for most of the frequency band, this is VERY different from the PSRR of a regular opamp. You might want to play around with some PSRR measurements for fully differential opamp filters / PGA stages etc and get an idea about how Power supply variation / noise actually translates (over frequency) to an output error. The process is not that simple. regards Robert --- In LTspice@..., Ganesan <dg1@...> wrote:
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Re: AD8336 failure
Tony Casey
--- In LTspice@..., "stm6823@..." <stevemorris@...> wrote:
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 |
Re: H-Bridge Controller Model
A suggested starting point is the following pdf. See:
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<> Howard On 9/14/2011 4:15 PM, amhtech wrote:
I am in the process of designing a motor controller circuit. A PIC microcontroller will create/control a PWM signal which will be "inputted" to an H-bridge controller which will drive a brushed DC motor either forward or reverse. |
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